LONDON: Prime Minister David Cameron on Tuesday called Iran a "disgrace" and warned of serious consequences after protesters stormed Britain's embassy in Tehran.
"The attack on the British Embassy in Tehran today was outrageous and indefensible," said Cameron in a statement.
"The failure of the Iranian government to defend British staff and property was a disgrace," he added. "We hold the Iranian government responsible."
The prime minister earlier chaired a meeting of COBRA, Britain's security response committee, after it emerged that its two compounds had been attacked.
"The Iranian government must recognise that there will be serious consequences for failing to protect our staff," vowed Cameron.
"We will consider what these measures should be in the coming days."
Cameron's comments followed earlier warnings from Foreign Secretary William Hague.
Hague said the assault on the embassy and another diplomatic compound in Tehran by young men chanting "Death to Britain" was a "grave breach" of the Vienna Convention which requires host countries to protect diplomats.
Cameron arranged the COBRA meeting in response to the storming, which has raised tensions in the West over Iran's contested nuclear programme.
France, the European Union and Russia -- Iran's closest ally -- also condemned the attack on the British facilities.
Six British diplomats held for more than two hours by hundreds of protesters inside a British diplomatic compound in the north of Tehran were freed when police intervened.
Dozens of protesters were shown on Iranian state television throwing stones at embassy windows, breaking them, and one was seen climbing the wall of the compound carrying a looted portrait of Britain's Queen Elizabeth II.
The attack comes amid heightened tensions following Iran's decision to pass a law to expel the British ambassador to Tehran in retaliation for new British sanctions that cut off all ties with Iran's financial sector.
The sanctions were part of a coordinated raft of measures announced on November 14 by Britain, the United States and Canada to increase pressure on Iran to halt its nuclear programme.
Iran insists it is not developing a nuclear weapon and that the programme is purely for energy purposes.
"The attack on the British Embassy in Tehran today was outrageous and indefensible," said Cameron in a statement.
"The failure of the Iranian government to defend British staff and property was a disgrace," he added. "We hold the Iranian government responsible."
The prime minister earlier chaired a meeting of COBRA, Britain's security response committee, after it emerged that its two compounds had been attacked.
"The Iranian government must recognise that there will be serious consequences for failing to protect our staff," vowed Cameron.
"We will consider what these measures should be in the coming days."
Cameron's comments followed earlier warnings from Foreign Secretary William Hague.
Hague said the assault on the embassy and another diplomatic compound in Tehran by young men chanting "Death to Britain" was a "grave breach" of the Vienna Convention which requires host countries to protect diplomats.
Cameron arranged the COBRA meeting in response to the storming, which has raised tensions in the West over Iran's contested nuclear programme.
France, the European Union and Russia -- Iran's closest ally -- also condemned the attack on the British facilities.
Six British diplomats held for more than two hours by hundreds of protesters inside a British diplomatic compound in the north of Tehran were freed when police intervened.
Dozens of protesters were shown on Iranian state television throwing stones at embassy windows, breaking them, and one was seen climbing the wall of the compound carrying a looted portrait of Britain's Queen Elizabeth II.
The attack comes amid heightened tensions following Iran's decision to pass a law to expel the British ambassador to Tehran in retaliation for new British sanctions that cut off all ties with Iran's financial sector.
The sanctions were part of a coordinated raft of measures announced on November 14 by Britain, the United States and Canada to increase pressure on Iran to halt its nuclear programme.
Iran insists it is not developing a nuclear weapon and that the programme is purely for energy purposes.