Tampa, Florida -- There is a worldwide travel alert for Americans because of a possible terror plot linked to al Qaeda.
Sources tell CBS News the threat is the most credible in years.
The notice came from the U.S. State Department and Jacqueline Wensink got nervous.
"I'm afraid for it, yes," said Wensink, who is finishing a vacation in Tampa Bay from the Netherlands. Wensink, along with her husband and daughters, planned to travel out of Tampa International Airport on Monday.
This weekend, the U.S. government warned it has a steady stream of intelligence showing people allied with al Qaeda may be planning terror attacks against Western targets, mainly in the Mideast and North Africa.
Wednesday marks 15 years since terrorists killed hundreds in bombings of American embassies in Africa.
The new global bulletin is the first since the 10th anniversary of the 9/11 attacks. It warns American tourists abroad to watch their surroundings and sign up for constant updates from the State Department.
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"We have heard about these warnings... just yesterday we were in our room, and we have talked about it," Jaqueline's husband Enrico said.
This family faced a choice. Do they stick with their plan and go from here to New York City for a few days?
The city is full of things specifically mentioned as common terrorist targets in the State Department's warning: subways, trains, airports, and boats.
Or do they bolt straight back home to the quiet of the Netherlands and lay low, away from all that?
They decided to stay and visit New York -- a vacation highlight they had promised their two daughters.
"It's, for me, the reason to go -- not for myself," Jacqueline said.
Both the operations team and the police department at Tampa International Airport say they are aware of the alert and are paying attention to it, but they've made no changes to procedures at TIA because of it.
Grayson Kamm, 10 News