Riot police clashed with hundreds of pro-reform protesters in Tehran and arrested dozens of them yesterday, a witness said, in the latest unrest over last month's disputed election.
Demonstrators were chanting slogans against President Mahmoud Ahmadinejad and the government, including: "Ahmadinejad – resign, resign" and "Death to dictators".
The witness said police beat protesters who had gathered in Haft-e Tir square in central Tehran, in defiance of a ban on such demonstrations put in place after the 12 June election, which the opposition says was rigged in favour of Mr Ahmadinejad.
"Riot police are taking dozens of protesters into their cars and they are taking them away," the witness said. "There are hundreds of riot police and plain clothes [security forces], beating people who gathered to support [opposition leader Mirhossein] Mousavi."
The clash erupted four days after similar confrontations between police and protesters for the first time in weeks on Friday after the former president Akbar Hashemi Rafsanjani declared the Islamic Republic in crisis and said there were doubts about the election result. The authorities reject opposition charges of vote-rigging.
The election stirred the most striking display of internal unrest in Iran, the world's fifth biggest oil exporter, since the 1979 revolution and exposed deep rifts in its ruling elite.
At least 20 people died in the post-election violence last month. Mr Mousavi and the authorities blame each other for the bloodshed. Riot police and religious Basiji militia suppressed the protests in June but Mr Mousavi has remained defiant. The opposition leader, who came second in the election, and the fourth-placed pro-reform cleric, Mehdi Karroubi, have continued to dispute the official election result, even though the Supreme Leader Ayatollah Ali Khamenei has endorsed Mr Ahmadinejad's election victory.
Earlier, Iran's police chief Esmail Ahmadi-Moghaddam accused the opposition of "inciting sedition" and said that his force would act firmly to uphold the law, the official Irna news agency reported.
The chief's deputy, Ahmad-Reza Radan, said there were rumours of new "illegal gatherings" in Tehran yesterday but that the security forces would confront any such protests, according to reports from the semi-official Fars News Agency.