Washington (CNN) -- The U.S. State Department is expected to issue a travel alert to Americans in Europe in light of recent terror threat information, U.S. officials said Saturday.
The alert could be issued as early as Sunday morning, according to one senior official.
The alert is expected to urge American citizens in Europe to be vigilant, especially when in public places such as public transportation, airports, and tourist sites, officials said.
It is not expected to warn Americans against travel to Europe, officials said.
One senior U.S. official said that in addition to the travel alert from the State Department, "U.S. military installations are taking prudent precautions. This is a serious situation".
A separate U.S. official said the alert is being prompted by the volume of intelligence on possible terror threats, rather than new intelligence.
CNN
