KABUL, Afghanistan (AP) - An Afghan official says 14 people have been killed in a militant attack on a Shiite shrine in the capital, Kabul.

The Interior Ministry's spokesman, Sediq Sediqqi, said on Tuesday another 26 people were wounded in the attack on the Sakhi Shrine.

He says that 13 civilians and one policeman were killed, and that three police were among the wounded.

Contrary to earlier reports of three gunmen, Sediqqi says only one gunman attacked the shrine. He was shot dead by police.

The attack took place as Shiites gathered ahead of Wednesday's Ashoura Day, which commemorates the death in 680 AD of the Prophet Muhammad's grandson, Imam Hussein.

THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below.

At least three gunmen wearing military uniforms attacked a Shiite shrine in Kabul on Tuesday, taking an unknown number of people hostage, an Afghan official said.

One of the gunmen was shot dead by police, while two remained inside the shrine, said Sediq Sediqqi, the spokesman for the Interior Ministry.

The Public Health Ministry spokesman, Ismail Kawasi, said that so far 18 people had been wounded and were admitted to hospitals around the city.

Shiites had gathered at the Sakhi Shrine, the largest in the capital, as part of annual commemorations for Muhharam, a month of mourning to commemorate the death of Imam Hussein - the grandson of the Prophet Muhammed - in Karbala, Iraq, in 680 AD.

On Wednesday, Shiites will mark Ashoura Day, the climax of the holy month, which in Afghanistan is a public holiday.

Kabul police had warned Shiites against large gatherings as attacks were expected. Lt. Gen. Gul Nabi Ahmadzia, the commander of the Kabul garrison, told The Associated Press on Monday that he had received credible reports that Ashoura activities would be targeted and called for Shiites to hold the ceremonies "within limits."

Shiites make up an estimated 15 percent of Afghanistan's population of around 30 million people. Most Afghan Shiites are ethnic Hazaras. Militant Sunni fundamentalists such as the Taliban and the Islamic State group view Shiites as apostates and frequently attack Shiite mosques and public gatherings.

A July suicide bomb attack on a public demonstration by Hazaras against discrimination killed at least 80 people and wounded more than 200.

In 2011, at least 54 people were killed when a suicide bomber detonated his device at another Kabul shrine where hundreds of people had gathered. A Shiite mosque in the northern city of Mazar-i-Sharif was hit at the same time, leaving four dead.