Several thousand Iranians, chanting "Death to America", demonstrated here Friday against alleged "atrocities" by US military forces in the Iraqi Shia holy city of Najaf.
They assembled in the capital's main Revolution Square after weekly prayers at Tehran University, in line with a call by officials angered by more than a week of deadly fighting between US forces and Shia militiamen in the city.
"Defend the mausoleum of the imam (Ali) with our blood," "White House, black heart," and "The Muslim nation will never forgive," chanted the protestors.
The imam leading the prayers, Ayatollah Ahmad Janati, told them that "the Americans will answer for their crimes on the day of the resurrection".
"We should thank those who are defending the (Imam Ali) shrine," he said, referring to the militia of Shia cleric Moqtada Sadr.
Janati said the United States was working to install the secular camp as rulers of Iraq.
The mausoleum in the central city of Najaf is one of the holiest sites for Shias, who also form the majority in Iran.
Several dozen of the protestors then made their way to Britain's embassy to demand the mission be closed and Ambassador Richard Dalton expelled.
However, a heavy cordon of riot police kept them from approaching the site.
London is Washington's main ally in Iraq and its relations with Tehran have recently taken a downturn.
The state news agency IRNA reported that similar anti-US demonstrations were held Friday across the country, including the cities of Isfahan, Kashan, Ahwaz and Bandar Abbas.