The United States has warned its citizens in Nordic and Baltic states of the risk of terror attacks in public places after receiving what it called "threat information".
The statements were posted at the weekend on the U.S. embassy Web site in Finland and Latvia.
"U.S. citizens in the Nordic and Baltic countries (should) be vigilant as to their surroundings, especially in centers of ground-based mass transit," the State Department said in a statement posted at the weekend on the U.S. embassy Web site in Helsinki.
"Report any unusual or suspicious persons, incidents or circumstances to the nearest police authorities," it said.
On the U.S. embassy Web site in Latvia, citizens were warned to avoid large shopping areas and transport hubs "on or about November 1".