File photo: Xinhua

Britain's Ambassador to Iran, Robert Macaire, was arrested during protests outside a university in the capital city Tehran.

According to Iranian state media, Macaire was detained and released an hour later.

According to the The Guardian, Macaire was said to have been one of a number of people held on suspicion of provoking and directing radical actions.

Protests began after the Iranian government admitted its forces shot down a Ukrainian passenger plane by mistake, killing 176 on board. 

The UK government accused Iran of violating international law by arresting its ambassador.