Britain's embassy in the Yemeni capital Sanaa will be shut this weekend, the Foreign Office said, after the United States announced the temporary closure of two dozen embassies over fears of an al Qaeda attack.
Several British embassy staff have been withdrawn from Sanaa over the security fears, a spokesman for the Foreign Office in London said.
"The embassy will be closed on the 4th and 5th of August," the spokesman said.
"We have withdrawn a number of staff from Sanaa, due to increased security concerns." He added: "We are particularly concerned about the security situation in the final days of Ramadan and into Eid." The Muslim holy month of Ramadan ends next week with the feast of Eid al-Fitr.
The United States had issued a worldwide alert on Friday warning of plans by al Qaeda to launch an attack in the Middle East or North Africa in August.
On Thursday, the US State Department had announced that at least 22 US embassies would close on Sunday as a precaution.
The State Department said attacks were possible "particularly in the Middle East and North Africa, and possibly occurring in or emanating from the Arabian Peninsula."
The Foreign Office advises British nationals against all travel to Yemen, and strongly advises any remaining Britons to leave the impoverished Arabian Peninsula country.
"Our travel advice advises particular vigilance during Ramadan, when tensions could be heightened," a ministry spokesman said.
On its website, the Foreign Office warns of a "high threat from terrorism throughout Yemen", and says British nationals face "a very high threat of kidnap from armed tribes, criminals and terrorists".
There are no current plans to close other British embassies this weekend, a Foreign Office spokesman told AFP.