Crowds chanted Death to Britain at Tehran University on Friday prayers as a hardline Iranian cleric warned the United Nations and European Union against siding with London after students and militia stormed the British Embassy in Tehran.

Cleric Ahmad Khatami denounced those, including the EU, who had tied themselves to the rotten rope of Britain, as a group involved in the embassy's ransacking prepared to give Iranian diplomats expelled from Britain a hero's welcome home.

Britain evacuated its diplomats from Tehran and closed down the Iranian Embassy in London after scores of Basij militia men and radical students sacked Britain's Tehran embassy and a residential compound on Tuesday.

In response, the biggest EU countries withdrew their ambassadors and the United Nations Security Council said it condemned in the strongest terms the attack.

Khatami told worshippers that the Security Council was showing itself to be as bad as Britain, which Iranian hardliners

believe is plotting to bring down their Islamic system.

Issuing a statement against Iran means falling into a well with the rotten rope of Britain, Khatami said to chants of Death to Britain.

Khatami also warned Britain's EU partners - which tightened sanctions on Tehran on Thursday over its disputed nuclear programme, and are considering banning Iranian oil imports - against closing ranks with London.

If you have just a bit of wisdom, you won't tie your rope to the rotten rope of Britain, he said.

Increasing tensions with the world's fifth biggest oil exporter pushed up global oil prices despite concerns of a sustained economic downturn in the West. Brent crude rose towards $110 a barrel on Friday.

In an unprecedented move, Iran's culture ministry banned foreign media from covering anti-British pro-government protests in Tehran, especially rallies in front of the British Embassy and the Qolhak compound unless authorized in advance, the ministry in a statement. Witnesses reported a heavy presence of police at Ferdowsi square, where the British embassy is located.

Life is normal in the area but there are many police officers in the area, said a witness who asked not to be named.

In 2009, the ministry banned foreign media from covering anti-government street protests that followed the contested re-election of President Mahmoud Ahmadinejad.

The semi-official Fars news agency reported on Wednesday that 11 hardline protesters detained for storming the British compounds had been released. Damaging property is punishable by a jail term of up to three years.

With international pressure on Tehran mounting, EU foreign ministers laid out the plans on Thursday for a possible embargo on Iranian oil in response to growing Western suspicions that the Islamic Republic aims secretly to develop nuclear weapons.

Iran says its nuclear programme is peaceful but the U.N. nuclear watchdog body issued a report last month which suggested it has worked on designing an atom bomb.

WELCOME HOME

Iranian diplomats expelled from London were due to arrive in Tehran in the early hours of Saturday and the Basij militia said it would have a welcoming committee for them at the International Imam Khomeini Airport outside the capital.

Iran's Foreign Ministry expressed regret over the embassy invasion, which it said was a spontaneous overflowing of anger during a peaceful protest by students.

However, Britain says there must have been at least tacit approval by the ruling establishment.

The Iranian reformist website Sahamnews issued a statement by a group of students at the Islamic Azad university condemning the attack and saying the conservative hardliners did not represent the view of most young Iranians.

Misusing the name of student is something we cannot easily let pass. There is no connection between what these people did and the honourable and sensible Iranian students, the statement said.

Iran's top authority, Supreme Leader Ayatollah Ali Khamenei, and Ahmadinejad have yet to comment publicly on the attack - underscoring the view of analysts that the faction-riven government has mixed feelings about an event likely to lead to deeper international isolation of Iran.

Parliamentary speaker Ali Larijani, a long-time rival to Ahmadinejad, immediately condemned the U.N. Security Council reaction to the embassy storming as hasty and devious.

British diplomats were evacuated after their offices and living quarters were ransacked.

The historic 135-year-old embassy residence in a wooded compound in downtown Tehran, used by the ambassador to host official dinners, was said to have been systematically destroyed during the onslaught.

One Western diplomat who visited the scene on Thursday said priceless oil paintings had been slashed and that the protesters had cut the face out of a portrait of Queen Victoria. There were no reports of harm to diplomatic staff.

(Additional reporting by Parisa Hafezi; Writing by Parisa Hafezi and Robin Pomeroy)