LONDON - BRITAIN is withdrawing the families of embassy staff working in Iran because of post-election violence, the Foreign Office said on Monday.

The decision follows a week of demonstrations on the streets of Tehran by protesters angry at a presidential election which returned Mahmoud Ahmadinejad to power. Iranian security forces have led the violent crackdown on the widening protests.

'The ongoing violence has had a significant impact on the families of our staff who have been unable to carry on their lives as normal,' a Foreign Office spokesman said.

'As a result, we are withdrawing dependents of embassy staff until the situation improves.'

Last week, Iran's Supreme Leader Ayatollah Ali Khamenei described Britain as 'the most treacherous' of Iran's enemies, prompting Foreign Office protests and the summoning of a senior Iranian diplomat in London for consultations.

Britain has a large embassy in Iran. It is not clear how many family members and dependents will be evacuated.

Officials said they did not expect to have to withdraw any diplomats at this stage.

'We do not believe that it is necessary to reduce the number of staff at this time, however, we are monitoring the situation with the utmost vigilance,' the spokesman said.

Britain has been cautious in its comments on the Iranian election, not wanting to be seen to interfere in another country's affairs. However, at the weekend Prime Minister Gordon Brown condemned the violence against protesters.

At least 10 people were killed and more than 100 wounded in demonstrations in Tehran on Saturday, according to Iranian state television, as thousands of protesters defied a warning from Khamenei for the demonstrations to stop. -- REUTERS