Some 400 male and female members of the militia, a volunteer branch of the Iranian Revolutionary Guards, were kept away from the embassy walls and main gate by dozens of anti-riot police.
The demonstrators chanted slogans calling for the expulsion of Britain’s ambassador, Richard Dalton, and for the embassy to be shut down. They also demanded a boycott of British goods and a halt in trade with London.
After torching British, American and Israeli flags, some elements in the crowd then threw stones at the embassy, although police prevented them from getting too close.
The embassy was the target of a string of angry demonstrations earlier this year against US-led coalition attacks inside the Iraqi Shiite holy shrine cities of Najaf and Karbala, as well as against the abuse of Iraqi prisoners.
Some of the protests saw Islamist radicals attempt to storm the compound, prompting clashes with security forces. The rallies have also been marked by the throwing of home-made bombs and stones.
Britain’s embassy has yet to replace the windows shattered in the protest, fearing they will only be broken again.
The US embassy in Tehran was stormed by Islamist students after the 1979 revolution, triggering a 444-day hostage crisis and the breakoff of diplomatic relations between Washington and Tehran.
