Reformist Mirhossein Mousavi has demanded that Iran's disputed presidential vote be annulled.

The defeated presidential candidate formally asked Iran's Guardian Council legislative body to cancel the election result and urged his supporters to continue to protest "in a peaceful and legal way".

Mr Mousavi's supporters again took to the streets after Saturday's violent demonstrations, which marked the sharpest expression of discontent against the Islamic Republic's leadership since the 1979 revolution.

Tens of thousands of Ahmadinejad supporters people also gathered to hail the conservative leader's win by 63 per cent of the vote - a surprisingly wide margin that provoked accusations of electoral fraud from his opponents.

A defiant Mr Ahmadinejad described the poll as "clean and healthy", dismissing complaints by defeated candidates as sour grapes.

He said: "They may be upset by their failure. They spent a lot of money to make propaganda (and) expected to win, so it is natural they are disappointed."

He warned that any country that attacked his own would regret it, saying: "Who dares to attack Iran? Who even dares to think about it?"

Iran's refusal to halt nuclear work, which Western governments suspect is aimed at making bombs, has sparked talk of possible US or Israeli strikes on its nuclear sites.

Police have detained more than 100 reformers, including the brother of former President Mohammad Khatami, a leading reformer said.

The Iranian Government is jamming BBC broadcasts to the country, the director of the Corporation's World Service has said.

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