Iranian protesters have stormed two British diplomatic compounds in Tehran in response to Britain's new economic sanctions against Iran.

Protesters Tuesday broke windows, scattered documents and pulled down a British flag. They also looted a portrait of Britain's Queen Elizabeth at one of the sites. Outside, protesters chanted “death to Britain.”

The British Foreign Office in London expressed outrage and said details are emerging.

Last week, Britain cut business transactions with all banks in Iran, including Iran's Central Bank, as part of coordinated sanctions with the United States and Canada.

The move was in response to Tehran's suspected program to develop nuclear weapons. It was the first time Britain has cut ties with the entire banking sector of a country.

New sanctions from Britain, the U.S. and Canada followed a report by the U.N. atomic energy agency strongly suggesting that Iran is researching nuclear weapons. Tehran says its nuclear activities are for civilian purposes.

On Monday, Iran's constitutional oversight body ratified a bill passed by parliament the day before to reduce diplomatic and economic ties with Britain.

The bill pushes the British ambassador out within two weeks, leaving Britain's embassy to be run by a charge d'affaires. Economic relations with London will also be reduced to a minimum.