Violence erupted again on the streets of Tehran last night after tens of thousands of supporters of Mahmoud Ahmadinejad poured into the capital to celebrate his disputed victory in Friday’s presidential election.

Hours after Mr Ahmadinejad boasted of his “epic achievement” to a huge rally in Tehran’s biggest square, swarms of basiji — the regime’s young paramilitary volunteers — engaged in battles with opposition supporters, who say that the President stole the election through blatant fraud.

A succession of Western governments challenged the election results. Joe Biden, the US Vice-President, said there was an awful lot of doubt about Mr Ahmadinejad’s victory over Mir Hossein Mousavi by a 28 per cent margin.

France condemned the “brutal reaction” of the security forces who rampaged across Tehran all weekend, using baton charges, teargas, rubber bullets and stun grenades to disperse incensed Mousavi supporters and Germany has summoned the Iranian ambassador to explain events after the election. Elsewehre, Afghanistan and Iraq issued their congratulations to Mr Ahmadinejad.

Binyamin Netanyahu, the Israeli Prime Minister, said that Mr Ahmadinejad’s re-election underscored the danger posed by Iran’s pursuit of nuclear weapons. “The greatest threat facing Israel, the Middle East and the whole of mankind is the encounter between extremist Islam and nuclear capabilities,” he said.

Asked about a possible Israeli strike against Iran’s nuclear facilities, Mr Ahmadinejad told reporters: “There’s not the slightest possibility anyone would make such a stupid mistake.”

Mr Mousavi, a former Prime Minister, has not been seen since Friday, but has issued statements urging supporters to continue their nationwide protests against the election “charade”: some results were announced before ballot boxes had even been opened. Last night he appealed to the Guardian Council, a powerful body of senior clerics, to declare the election void.

Zahra Rahnavard, Mr Mousavi’s wife, accused the President of “dictatorship”, saying: “The Iranian people voted to change Ahmadinejad, but this vote became a vote to solidify Ahmadinejad.”

Mehdi Karoubi, another reformist candidate, said he refused to recognise the “illegitimate” President, but Mr Ahmadinejad compared the protests to those of football supporters whose team has lost. “They are not important,” he said, adding that Iran’s form of democracy should be a model for the rest of the world to follow.

The crackdown on the opposition was ruthless and systematic. Huge numbers of stick-wielding riot police flooded the streets on foot and on fleets of motorbikes, wading into the groups of Mousavi supporters wherever they appeared. They were reinforced by thousands of flag-waving, gloating basiji.

Simultaneously the regime arrested several reformist leaders. It prevented the opposition mobilising by cutting mobile telephone and text services, jamming websites and independent news services, and censoring opposition newspapers. Foreign journalists are being ordered to leave the country.

In Tehran, Mr Mousavi’s supporters chanted their defiance as they burnt buses and rubbish skips and smashed the windows of banks during battles with the security forces.

They hope to stage a rally today in a central Tehran square, Enghelab, where many rallies were held during the 1979 Islamic revolution. Reports of unrest in other Iranian cities were impossible to confirm.

Mr Amadinejad told reporters it was absurd to question the legitimacy of an election in which 39 million voted, and he secured 63 per cent of the vote. He said the huge turnout, more than 80 per cent, showed Iran’s brand of religious democracy was better than Western liberal democracy. “Elections in Iran are the cleanest,” he said

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