The U.S. embassies in Latvia, Estonia and Finland are warning Americans in the Baltics of a possible terrorist threat.

The embassy Web sites say the U.S. State Department has received what it called "threat information" and urged all U.S. citizens in the region to avoid large public gathering areas, such as shopping centers and mass transportation.

The public warnings contained few specifics. An official at the embassy in Latvia confirmed the warning had been issued, but said she could provide no further information.

A spokesman for the Latvian Interior Ministry said Saturday that security services in Latvia are on a high state of alert after U.S., Estonian, and Norwegian authorities warned that an Islamic extremist group may be planning a terror attack.