Security has been tightened around a Beijing bar and shopping area popular with foreigners as embassies issued warnings that foreigners should be on guard for possible threats against them.

The American, British, French and other embassies said they had received information of possible threats against Westerners in the Sanlitun area on or around Christmas Day. They urged their citizens to be vigilant.

Armed police were standing on guard in the area, which has many big-name brand stores and some embassies.

Beijing police announced Thursday they had issued a yellow security alert to ensure safety during the Christmas period. According to Beijing's security regulations, the alert is issued in the case of the receipt of threats to safety or finding suspected explosives. Police commonly issue a yellow alert during holiday periods.