Iranian diplomats expelled from Britain after protesters stormed the British embassy in Tehran have arrived home to supporters bearing flowers and chanting.

"Spy embassy closed for good," read one of the many placards carried by the crowd of about 100 men and women, most of whom appeared to be members of the Basij armed group, congregated at Imam Khomeini Airport on Saturday.

Britain evacuated all diplomatic staff and closed its embassy in Tehran after it was stormed and ransacked on Tuesday.

France, Germany, Italy and the Netherlands withdrew their ambassadors from Tehran in protest.

On Friday, Rominick Chilcot, the British ambassador to Iran, said that it was likely that the attack had the support of Iran's leaders.

"Iran is not the sort of country where spontaneously a demonstration congregates and then attacks a foreign embassy," said Chilcot.

"That sort of activity is only done with the acquiescence and the support of the state, and there were a number of reasons why - with the benefit of hindsight - that this was a state supported activity."

Al Jazeera's Stefanie Dekker reports.