British embassy staff are being withdrawn from Iran after students stormed the building chanting ‘Death to England’, torching Union Flags and ripping down pictures of the Queen.
It is unclear how many staff are leaving, but the Foreign and Commonwealth Office said on Wednesday that concerns over the safety of British diplomats were paramout.
"The prime minister and foreign secretary have made clear that ensuring the safety of our staff and their families is our immediate priority. In light of yesterday's events and to ensure the ongoing safety, some staff are leaving Tehran," a spokesman said.
Tuesday's break-in comes two days after the Iranian parliament voted to downgrade relations with the United Kingdom, which could see the British Ambassador expelled from he capital.
Prime Minister David Cameron branded the Iranian government a "disgrace", saying: "The attack on the British Embassy in Tehran today was outrageous and indefensible. The failure of the Iranian government to defend British staff and property was a disgrace.
"The Iranian government must immediately ensure the continued safety of our staff, return all property and secure the compound immediately."
Foreign Secretary, William Hague said the attack was a "grave breach of the Vienna Convention which requires the protection of diplomats and diplomatic premises under all circumstances.
"We hold the Iranian Government responsible for its failure to take adequate measures to protect our Embassy, as it is required to do."
British nationals living in Iran have been urged to stay indoors and the FCO has revised its travel guidance on the country.