TEHRAN (AFP) – A tense Iran was gearing up on Monday for more street protests against the disputed re-election of President Mahmoud Ahmadinejad after authorities banned a nationwide march by his defeated rival.

Mir Hossein Mousavi, a wartime prime minister who lost to Ahmadinejad by a wide margin in Friday’s vote, lodged a formal appeal on Sunday calling for the results of what he has branded a vote-rigged “charade” to be annulled.

But the interior ministry said it would not allow Mousavi’s supporters to hold a nationwide rally on Monday, after two days of street protests and some of the worst rioting in Tehran in a decade.

“No authorisation for a march or gathering has been issued and any kind of gathering or march is illegal,” a ministry official told AFP.

The reformist Sarmayeh newspaper also reported that Mousavi’s newspaper Kalameh Sabz (Green Word) has been suspended and it was not available on newsstands in Tehran.

Ahmadinejad himself addressed a victory rally of vast crowds of supporters in Tehran on Sunday, defending the results of an election that has highlighted deep divisions in Iran after three decades of Islamic rule.

“Elections in Iran are the cleanest,” he said. “Today, we should appreciate the great triumph of the people of Iran against the united front of all the world arrogance (the West) and the psychological war launched by the enemy.”

The authorities have warned that they would crush any “velvet revolution” in Iran and police said they have rounded up 170 people over the protests, including a number of reformist leaders.

Relatives of those arrested protested outside Tehran’s main revolutionary court. “You can beat us as much as you can, but take us to our children,” shouted a woman as a policeman nearby was beat a man in order to disperse the crowd of around 200.

Riot police on Sunday fired into the air to break up a demonstration, while about 200 Mousavi supporters shouting “Death to the dictator!” lobbed stones at police who fired back with tear-gas.

On Saturday, Tehran witnessed widespread clashes between baton-wielding police and stone-throwing protestors who set bins and vehicles on fire in violence on a scale not seen since 1999 when student demonstrations led to a week of deadly nationwide unrest.

The 52-year-old hardline Ahmadinejad insisted on his landslide victory before a massive sea of loyalists on Sunday, saying the election was like a football match and the loser should just “let it go.”

But Mousavi, 67, who mustered a massive opposition movement of green-clad supporters but has not been since the election, said he has lodged an appeal with the powerful Guardians Council to cancel the results, alleging blatant irregularities and cheating.

The 12-member council will announce its decision on the election in 10 days, spokesman Abbas Ali Kadkhodai said.

US Vice President Joe Biden said on Sunday there was “an awful lot of doubt” about the vote, but nevertheless reiterated Washington’s willingness to engage in talks after three decades of severed ties.

Washington has extended a hand for dialgoue with Tehran since President Barack Obama took office in January.

European nations voiced concern at what Germany called “unacceptable” action by security forces, while a number of media organisations have reported the arrest or harassment of their journalists covering the dramatic events.

Amnesty International called for the Iranian authorities to immediately investigate the crackdown on demonstrators.

“The shocking scenes of violence meted out by the security forces need to be urgently investigated and those responsible for human rights violations must be brought to justice,” it said.

Iranian analysts have warned that the disputed nature of Ahmadinejad’s victory could weaken Iran from within and isolate it further from the outside world.

“The perception of many Iranians that their vote was not taken into consideration will weigh heavily on the legitimacy of future elections,” said Tehran-based analyst Sayeed Laylaz.

“Now the word ‘cheating’ has entered the political vocabulary of the country.”

The election campaign, unprecedented in its fervour with mass carnival-like street rallies and the hurling of insults between candidates, appears to have galvanised a grass-roots push for change.

But it highlighted deep divisions in society, with Ahmadinejad commanding massive backing in the rural heartland and among the poor, while Mousavi gained ground among the urban youth calling for a less confrontational stance towards the West and easing restrictions in society.

Karim Sadjadpour of US-based Carnegie Endowment for International Peace said Ahmadinejad appears to have been the winner right from the start.

“In retrospect, it looks like the entire campaign was a show, in the sense that (supreme leader) Ayatollah (Ali) Khamenei was never going to let Ahmadinejad lose,” he said.

Khamenei has the final say on all strategic matters and has urged the country to unite behind Ahmadinejad, who during his first term set Iran on a collision course with the international community over its nuclear drive, his anti-Israeli tirades and restrictions on society.

Sadjadpour said Ahmadinejad’s win increases the possibility of an Israeli military strike on Iran “significantly.”