Authorities said 21 people remained in critical condition Sunday after a rampage at the iconic London Bridge and a nearby market that left seven dead and dozens more injured.
Three suspected terrorists also were killed in Saturday night's attack, the third in Britain in less than three months.
"It is time to say enough is enough," Prime Minister Theresa May said Sunday. She called for tougher measures to contain Islamic extremism, saying the recent attacks are not directly linked, but “terrorism breeds terrorism.”
“They are bound together by the single evil ideology of Islamist extremism that preaches hatred, sows division, and promotes sectarianism,” she said. “It is an ideology that claims our Western values and freedom, democracy and human rights are incompatible with the religion of Islam."
No group has claimed responsibility for the attack. Eyewitnesses said they heard the men shout "this is for Allah,” British media reported.
Below is a timeline of events in the London terror attacks. All times are local for London.
PHOTOS: Terror attacks in London
France's foreign minister has announced that a French citizen was among those killed in the London attacks and that another remains missing.
Foreign Minister Jean-Yves Le Drian said on Sunday that seven other French nationals are hospitalized, four of them in serious condition.
French officials had earlier said that four French were injured in the Saturday attacks on London Bridge and at nearby restaurants and pubs. Le Drian revised the count upward hours later.
The minister tweeted that he was traveling to London on Monday.
A resident of a suburban London town where police have conducted a raid says he thinks one of the London Bridge attackers was a neighbor who was known for religious proselytizing.
Jibril Palomba said he recognized the man who lived in an apartment armed police raided early Sunday in Barking as one of the dead assailants in a widely published photo.
Palomba says he and his wife first encountered the neighbor after his wife became concerned about how the man spoke to their children and others in a local park "about religion, Mohammed, this kind of stuff."
He says his wife reported the neighbor's behavior to police, but nothing came of it.
Palomba says he later became friendly with the man and never suspected he could be planning attacks.
Social media giants Google and Twitter are responding to British Prime Minister Theresa May's statement that internet companies are complicit in terror attacks by giving extremist views "the safe space it needs to breed."
Representatives for the two companies issued statements on Sunday saying they've been working to improve the technology to identify and remove inappropriate content, including posts and files that are terror-related.
Nick Pickles, UK head of public policy at Twitter, said: "We continue to expand the use of technology as part of a systematic approach to removing this type of content."
Google said, "We are committed to working in partnership with the government and NGOs to tackle these challenging and complex problems, and share the government's commitment to ensuring terrorists do not have a voice online."
London police haven't said what role, if any, social media or information from the internet factored into Saturday night's attack that killed seven people.
Cricket rivals India and Pakistan have held a minute's silence for the victims of the London Bridge attacks amid enhanced security at the Edgbaston ground in Birmingham, England.
The West Midlands venue was hosting a game on Sunday as part of the two-week Champions Trophy tournament, which involves eight countries, including England.
World cricket's governing body says extra security had been put in place after the Saturday night attacks in the capital.
The International Cricket Council said in a statement that all team hotels went into lockdown and teams, match officials and staff were all quickly accounted for after the attacks.
Canadian Prime Minister Justin Trudeau says a Canadian is among those killed in the terrorist attack in London.
Trudeau said in a statement Sunday he is heartbroken.
Trudeau says Canada strongly condemns the senseless attack and stands united with the British people.
He says the Canadian government will not provide more details about the citizen killed in Saturday night's attack out of respect for the family.
British Prime Minister Theresa May has paid a private visit to some of the victims of the vehicle and knife attacks in central London.
May visited King's College Hospital, which is caring for 14 of the 48 people hospitalized after the Saturday night attacks on London Bridge and at nearby restaurants.
The National Health Service says 21 people remain in critical condition.
A van mowed down pedestrians on the bridge before its occupants got out and started stabbing people. Police shot three attackers dead.
Hundreds ran for their lives in the chaos.
Former Secretary of State John Kerry says Britons are going to have to sort out whether tolerance of extremism has gone on for too long, as British Prime Minister Theresa May has said.
Kerry tells NBC's "Meet the Press" that "a lot of ingredients" went into the attacks on London Bridge and at nearby restaurants Saturday night that left seven dead and nearly two dozen injured. Twelve people have been arrested.
He says one of the issues the country needs to get a handle on is the experience of Muslim residents, who've "had a long-standing problem with respect to greater levels of alienation, a harder time assimilating into the broader British society."
Kerry says the answer lies in building community to lessen the distance between governments and their people, a gap he thinks is a problem "all over the world."
Germany's Foreign Ministry says German citizens were among the people wounded in the attack in London, and one of them has serious injuries.
No further details were available Sunday on the Germans who were injured or the exact number.
In all, dozens of people were injured in the attack Saturday night on London Bridge and nearby Borough Market.
A Romanian chef has been hailed as a hero on social media after he took in some 20 terrified people in the bakery where he worked as attackers targeted restaurants and bars in Borough Market.
Florin Morariu, who works at the Bread Ahead bakery in the market, told The Associated Press: "We were looking out of the window because we saw that everyone was agitated, everyone was running, people, women... they were fainting, falling and we went outside to see what was happening."
He said when he went outside and saw two people stabbing others, he at first "froze" and didn't know what to do. But then he went and hit one of the attackers on the head with a crate.
"There was a car with a loudspeaker saying 'go, go' and they (police) threw a grenade.... and then I ran."
He added that when he saw that "people were desperate," he let about 20 people into the bakery and pulled the shutters down.
At least 7 dead and 48 wounded in terror attack and Mayor of London says there is "no reason to be alarmed!"— Donald J. Trump (@realDonaldTrump) June 4, 2017
France's minister for Europe says that four French citizens are among the dozens of wounded in the London terror attack that killed seven people.
Marielle de Sarnez expressed her condolences to the families affected and "absolute solidarity" with the British in a statement on Sunday.
Meanwhile, French Prime Minister Edouard Philippe visited a crisis center at the French Foreign Ministry that fields calls from anxious citizens after attacks.
Philippe noted the attack came as French living overseas begin voting in advance of June 11 first-round legislative elections. He said voting in London would continue with reinforced security.
The British Transport Police chief says that an officer who was wounded in the London Bridge attack was armed only with his baton when he confronted the three knife-wielding assailants.
The officer, who was stabbed in the face, head and a leg, was one of the first responders.
British Transport Police Chief Constable Paul Crowther visited the officer at a hospital and said that he's in stable condition. Crowther said that "it became clear that he showed enormous courage in the face of danger."
Crowther added that "for an officer who only joined us less than two years ago, the bravery he showed was outstanding and makes me extremely proud."
Seven people died in the attack and dozens were wounded. In addition, the three attackers were killed by police.
British police say they have arrested 12 people in east London over the attack in the London Bridge area.
Police said in a statement that the arrests were made Sunday morning in Barking by counterterrorism officers.
Officials said that seven people died in the Saturday night attack and roughly 48 were wounded. A British Transport Police officer and an off-duty officer were among the injured. In addition, three attackers were shot dead by police.
Police say the investigation is progressing rapidly. Prime Minister Theresa May has blamed Islamic extremists.
Britain's interior minister says the country's terrorism threat level will not be raised because police believe there are no perpetrators still on the loose.
Home Secretary Amber Rudd says "we don't believe there are additional elements" at large.
The level was raised to "critical" for several days after the March 22 concert bombing in Manchester, as police raced to track down the attacker's possible accomplices.
It now stands at "severe," meaning an attack is highly likely.
Three men were shot dead by police on Saturday, minutes after a van mowed into pedestrians on London Bridge and multiple people were stabbed around nearby Borough Market. Police say seven people were killed and 48 hospitalized.
Rudd told ITV television that more must be done to fight the "onslaught of jihadi propaganda that is radicalizing people online."
Arab Gulf countries and Turkey are condemning the attack in London that left six people dead and more than 40 others injured.
The United Arab Emirates, Qatar, Bahrain, Oman and Kuwait issued separate statements condemning such attacks and expressing their support for the British government.
The Saudi Embassy in the U.K. called on their citizens in London to exercise caution in crowded areas and follow police instructions.
In Turkey, the foreign ministry has expressed its "deep sadness." The ministry says that as "Turkey and the Turkish people, who have been subjected to similar attacks many times, we understand and share the pain of the people of the United Kingdom."
The ministry emphasized Turkey's readiness to support the U.K. in its fight against extremism
The attack in London Bridge, a busy area filled with hotels and restaurants, has left many visitors and tourists stranded after police cordoned off a large area near the crime scene. Many spent the night in improvised sleeping spaces, from the floors of hotel bars or restaurants to chairs of conference rooms.
Sue and Jason Dunt and a second couple, Richard and Michelle Orme, were out enjoying a post-matinee dinner on London's Embankment on Saturday. They tried to make it back to their hotel but were stymied by the police cordon thrown up around the attack site, and eventually found shelter in another hotel's conference room.
"We were wandering the streets until three in the morning," said Richard, a 40-year-old retail worker.
"There were people sleeping in the sofas in the reception and the restaurant. It was really good of them," he added.
Pope Francis has offered prayers for the victims of the London attacks during a traditional Sunday blessing following Mass that marked the Pentecost holiday.
Francis invoked prayers that the Holy Spirit "grants peace to the whole world and heal the wounds of war and of terrorism, which also last night, in London, struck innocent victims."
The pope asked for prayers for the victims and their family members caught up in the attack in London Bridge Saturday, which left seven dead and almost 50 wounded.
Pentecost concludes the Easter season.
British media are reporting an armed police operation taking place in east London. Scotland Yard declined to comment about the reports of the raid, or say whether the operation was linked to Saturday's attacks in London Bridge.
Footage from Sky News and social media show a police cordon around an apartment building in Barking, a suburb in east London.
Authorities have said officers shot dead all three attackers in Saturday night's attack, which left seven people dead, but that the investigation is continuing.
This version corrects the day of the attack to Saturday.
Spain's Foreign Ministry says that one Spaniard is among the dozens wounded in the London attack.
A ministry spokeswoman has told The Associated Press that the Spanish man has been taken to a hospital where he is being treated for wounds described as not serious. The spokeswoman spoke anonymously in line with ministry policy.
Spain's King Felipe VI and Prime Minister Mariano Rajoy have expressed their condolences for the victims of the attacks.
The Spanish Royal Family wrote on Twitter: "The British people will overcome this barbarism and senselessness. We are united today in pain and in our tireless defense of freedom."
--By Joseph Wilson in Barcelona.
Iran's Foreign Ministry spokesman is condemning the "terrorist attacks" in London and expresses sympathy for the families of the victims.
State TV is reporting that Bahram Ghasemi says an increasing number of extremist attacks is "an alarming signal for the global community."
He condemned terrorism in "all shapes and aspects regardless of purpose and motive."
Prime Minister Theresa May has strongly condemned the recent terror attacks in London and Manchester, saying "enough is enough" - and tougher measures are needed as "terrorism breeds terrorism" and attackers copy each other.
May was speaking a day after three attackers left seven dead in an onslaught in the London Bridge area - the third deadly attack in Britain since March.
She said that while the recent attacks are not connected, they are all bound by the "single evil ideology" that says Western values are incompatible with Islam.
She added that British authorities have disrupted five credible plots since March.
Manchester Police say security will be increased for the highly-anticipated Ariana Grande benefit concert later Sunday.
The One Love Manchester event will take place as planned but with extra protection.
Assistant Chief Constable Garry Shewan said Sunday there will be additional security checks and everyone will be searched at the Manchester event. Armed police will also attend.
Grande was performing when a bomber attacked her Manchester Arena concert on May 22, killing 22 people. She will be joined at Sunday's benefit by Katy Perry, Cold Play, Justin Beiber and others.
Grande has been meeting with some attack victims being treated in Manchester hospitals in recent days.
Russian President Vladimir Putin says the London Bridge attack is "shocking in its cruelty and cynicism."
Putin made the statement in a telegram of condolences Sunday to British Prime Minister Theresa May, according to the Kremlin website.
The statement said Putin "expressed his confidence that the response to the incident should be the escalating of joint efforts in the fight against the forces of terror around the world."
Russia has suffered many attacks over the past two decades, most recently the April 3 suicide bombing on a St. Petersburg subway train that killed 16 people.
The right-wing UK Independence Party has broken with other parties by announcing it will continue its general election campaign despite the terrorist attack.
Party chief Paul Nuttall said Sunday that a second disruption to the campaign similar to the one that followed the Manchester attack on May 22 is "precisely what the extremists would want us to do."
He said that could lead to more attacks.
Most parties have suspended campaigning before the June 8 general election.
London's police chief says the death toll from the terror attack in London Bridge has risen to seven.
Metropolitan Police Commissioner Cressida Dick told reporters that seven members of the public have died, in addition to the three suspects who used a van to attack people on London Bridge then stabbed others in the nearly Borough Market Saturday night.
The three attackers were shot dead by police within minutes.
Dick said police believed that the incident was under control, but a large police cordon remained in place in the area, south of the Thames, Sunday.
She added that police patrols will be increased in London, including those by armed officers.
Dozens of heavily-armed London police have fanned out across Borough Market and the streets outside London Bridge train station.
Many of the police were wearing face masks as they arrived Sunday morning to patrol the scene, where attackers using a van and knives left six people dead and more than 40 others injured. Police say officers shot dead three attackers within minutes of receiving the first call Saturday night.
London Mayor Sadiq Khan said Londoners can expect an increased police presence in the coming days.
Britain's Labour Party and the Scottish National Party have announced a suspension in campaigning for the general election because of the terror attack in the London Bridge area Saturday that left six dead.
They joined the Conservative Party in halting campaigning ahead of the June 8 vote.
There was a similar hiatus after the attack in Manchester killed 22 people last month. It is not clear when national campaigning will resume.
Prime Minister Theresa May had called the snap election in a bid to bolster her party's strength in Parliament ahead of Brexit negotiations.
European leaders have voiced solidarity with the British government and expressed condolences to the victims in the London attacks that left six dead.
Spanish Prime Minister Mariano Rajoy wrote in Spanish on his Twitter account: "I am following with great concern the attacks in London, sad news. Our solidarity and support for the British people and authorities."
Italian Premier Paolo Gentiloni tweeted Sunday: "Solidarity with the British government and a shared effort against terrorism. We are united in memory of the victims."
Gentiloni was host of the Group of Seven summit in Sicily on May 26-27 during which leaders pledged new measures to combat terrorism including pressuring internet providers and social media to more swiftly remove terror propaganda from the web.
Philippine President Rodrigo Duterte has expressed his sympathies to the victims of the London attacks, even as his troops struggled to end a deadly siege of a southern city by Islamic State group-aligned local militants.
Duterte's spokesman Ernesto Abella says "acts such as these touched not only the people of London, they also touched all peace-loving people in the global community."
Indonesia, the world's most populous Muslim nation, also condemned the attacks and reaffirmed its support and solidarity with Britain in its efforts to combat "radicalism and terrorism."
Indonesia too has been battling Muslim militants groups that have staged attacks across the sprawling archipelago, including in the capital Jakarta.
French President Emmanuel Macron says French citizens are among the wounded in Saturday's London attack.
In a statement Sunday denouncing the "abominable and cowardly" attack, Macron said France will continue fighting "terrorism with all our strength alongside Britain and all other countries concerned."
Macron said French authorities would work to help the French victims and increase security for French voters in London casting ballots in legislative elections starting Sunday "to show the force of democracy in the face of enemies of freedom."
London has a large French population and attracts many French visitors. French people were also among those injured in the attack on Westminster Bridge in March.
France is still under a state of emergency after a string of Islamic extremist attacks.
German Chancellor Angela Merkel is expressing solidarity with the people of London following the attacks in the British capital.
Merkel said in a statement Sunday that she learned with "sadness and dismay" of the attacks in the London Bridge area Saturday night.
She said that "today, we are united beyond all borders in horror and sorrow, but also in determination."
She stressed that "in the fight against every form of terrorism, we stand firmly and with determination at Britain's side."
Britain's Conservative Party has announced that it is suspending national campaigning ahead of the general election on June 8 as a result of the terror attacks in London.
Prime Minister Theresa May's party said there will be no national campaigning Sunday. It is not clear if campaigning will resume in the final days before the vote.
The opposition Labour Party has not yet announced its plans for Sunday.
Saturday night's attack on London Bridge, which left 6 killed and dozens injured, came just days ahead of the election.
London Mayor Sadiq Khan says some of those injured in the attacks on the city are in "critical" condition.
Six people were killed and more than 40 people were injured and treated at hospitals after attackers used a van to barrel into pedestrians on London Bridge, then attacked people in bars and restaurants nearby with knives on Saturday.
Khan said Sunday that Londoners should all remain vigilant as the terrorist threat level is severe. But he added: "I'm reassured we are one of the safest global cities in the world."
Khan says the militants want to disrupt Britain's democracy and hamper plans for voting in the general election June 8.
He praised emergency services and said police would make a statement after an emergency cabinet meeting.
India's Prime Minister Narendra Modi has condemned the attacks in London, saying they caused shock and anguish.
He says in a brief statement after returning from Europe that his thoughts are with the families of the deceased and offered prayers for the injured.
Police specialists are collecting evidence in the heart of London after a series of attacks described as terrorism killed six people and injured more than 30 others.
Prime Minister Theresa May planned to chair an emergency security Cabinet session Sunday to deal with the crisis.
The assault began when a van veered off the road and barreled into pedestrians on London Bridge. Witnesses say three men fled the van with large knives and attacked people at bars and restaurants in nearby Borough Market.
More than 30 victims are being treated at London hospitals and a number of others suffered less serious injuries.
The Metropolitan Police force declared the attacks "terrorist incidents." Assistant Commissioner Mark Rowley says while they believe all the attackers were killed, the investigation continues.