from the website of the Iranian Embassy in the UK:
Iranian Embassy - London: Iran regrets some protestersī actions
"On Tuesday, hundreds of Iranian students from different universities entered the compound of the British embassy in Tehran and pulled down Britainīs flag. However, police prevented them from entering the embassy itself.
In a statement released later on Tuesday, Iranīs Foreign Ministry expressed regret over the unacceptable actions of a few protesters despite the efforts of Iranian security forces to stop them.
According to the statement, relevant officials have been asked to immediately conduct necessary investigations with regards to this issue.
Stressing the Islamic Republicīs respect for international law and the immunity of diplomatic buildings, Iranīs Foreign Ministry also reiterated the Iranian governmentīs commitment to protect the diplomatic missions.
Police say the situation is under control, and security forces are trying to remove students who have entered the British embassy compound.
Police say they are protecting the embassy building and the documents inside, dispersing the large crowds gathered outside the embassy compound.
In northern Tehran, police entered a second British diplomatic compound to bring the security situation there under control.
Police say all foreign nationals in the compound are under protection of security forces"
I find that last sentence that I've highlighted rather disturbing