EDITOR'S NOTE: Iranian authorities have barred journalists for international news organizations from reporting on the streets and ordered them to stay in their offices. This report is based on the accounts of witnesses reached in Iran and official statements carried on Iranian media.

A top Iranian cleric said Friday that some of the detained Iranian staffers of the British Embassy in Tehran will be put on trial, and he accused Britain of a role in instigating widespread protests that erupted over the country's disputed presidential election.

The announcement by Ayatollah Ahmad Jannati alarmed European nations and fueled calls for tougher action against Tehran. Britain is pressing for members of the European Union to pull their ambassadors out of Tehran to protest the arrest of its embassy staffers last week — a step that the EU so far has hesitated to take.

After Jannati's comments, French President Nicolas Sarkozy on Friday expressed backing for Britain, saying "our solidarity with our English friends is total." He said France backs sanctions "so that Iranian leaders will really understand that the path that they have chosen will be a dead end."

The United States and Europe have been wary of reacting too harshly in Iran's post-election crisis, even as the government cracked down heavily on protests that erupted following the declaration of a landslide victory for incumbent Mahmoud Ahmadinejad in the June 12 presidential election. The West has been hoping to keep open prospects for future dialogue with Tehran — particularly over its controversial nuclear program.

Jannati, a powerful hard-liner who is close to Iran's supreme leader, told worshippers during a Friday prayer sermon at Tehran University that the detained staffers "made confessions."

"In these events, their embassy had a presence," he said, referring to the post-election turmoil. "Some people were arrested. Well, inevitably, they will be put on trial."

He did not say how many staffers will be tried or on what charges. Earlier Iranian officials said all but one of the nine embassy personnel originally arrested had been released, but British officials say two are being held.

In London, Foreign Secretary David Miliband said Britain is "deeply concerned" about the staff members.

Britain is "confident that our staff have not engaged in any improper or illegal behavior," Miliband said in a statement, adding that the ministry was seeking urgent clarification from Iranian authorities and that he would speak with Iranian Foreign Minister Manouchehr Mottaki about the issue.