Scores of protesters incensed by European Union moves to send Iran's nuclear case to the UN Security Council hurled stones and smoke bombs over the walls of the British embassy compound in Tehran on Wednesday.
The violence, easily contained by riot police, coincided with a vote by lawmakers to speed discussion of a bill that would force the government to scale back its co-operation with the UN atomic watchdog, state media reported.
The bill to limit the scope of nuclear inspections is in retaliation for a resolution approved by the International Atomic Energy Agency (IAEA) board of governors last week recommending Iran's case be sent to the UN Security Council.
If approved, the bill would oblige the government to stop implementing the Additional Protocol of the nuclear Non-Proliferation Treaty (NPT) which allows UN inspectors to make short-notice visits to nuclear facilities. About 300 protesters gathered outside the British embassy in Tehran on Wednesday to denounce the IAEA resolution submitted by Britain, France and Germany.
"Nuclear energy is our legitimate right," they chanted. "We will fight, we will die, we will never surrender."
During the protest, organised by the hard-line Basij militia, British and US flags were burned. Groups of protesters hurled stones, tomatoes and smoke bombs into the walled compound and some tried to push past police to reach the embassy's main gate.
Young women in black head-to-toe chadors held placards which said: "We are your serious enemies" and "The den of the old fox should be closed" - a reference to London's reputation for cunning and deceit in Iran.
One protester, his forehead cut by a police baton, left two bloody handprints on the embassy's brass name plate.