A terrorist threat in the Pakistani capital, Islamabad, forced the closure of the British embassy there. Pakistan's government is seeking to calm fears over the situation.
Pakistan's Foreign Ministry said Monday that it had received warning of a specific, credible threat to the embassies of the United States and Britain.
Both the U.S. Embassy and British High Commission are located in the center of Islamabad, in a diplomatic enclave, not far from Pakistan's parliament and other government buildings.
Foreign Ministry Spokesman Masood Khan says authorities are alert to the threat, and that the situation is under control.
"Security around these two missions has been beefed up, and there is no cause for worry, because all the precautionary steps have been taken," he said.
The closure forced the cancellation of a U.S. diplomatic reception Monday, meant to celebrate a U.S. national holiday. Embassy staff also sent e-mail messages to U.S. nationals warning them "to avoid the area around the American Embassy compound."
A diplomatic source, commenting on the closure of the British High Commission, said the rare step was taken out of concern for the safety of the embassy staff.
He declined to say how long it would be closed.
The United States and Britain were allies in the war last year to overthrow the Iraqi regime of Saddam Hussein, an action deeply unpopular among many Pakistanis.
U.S. diplomatic facilities have been repeatedly targeted in Pakistan, most recently in March, when police foiled an attempted car bombing of the U.S. consulate in the southern port of Karachi.