The UK Foreign Office said the temporary measure was imposed because Friday's expected demonstrations in the capital Sanaa may become violent.A statement said a small core staff would remain in place.
It came as Yemen
's president Ali Abdullah Saleh offered to step down by the end of the year in a bid to appease opposition groups.His overtures did little to quell protesters' efforts to force him out after 32 years in power.
Concerns are growing among Western governments that the Arab state could descend into chaos.
I think things are obviously, or evidently, very unsettled in Yemen. I think it's too soon to call an outcome. Saleh has been an important ally in the counter-terrorism arena.
US defence secretary Robert Gates
Yemen is perceived as having become a haven for al Qaeda - with its longstanding president seen as a key ally against the terrorist group.
