Iranian opposition supporters defied a ban on public protests on Friday to stage their first rally over the country's disputed presidential elections in more than a week.
Demonstrators took to the streets near Tehran University, where former President Ali Akbar Rafsanjani delivered a sermon challenging Iran's leaders.
The demonstration was the latest in a series of protests over the disputed election of 12 June, in which President Mahmoud Ahmadinejad was declared the winner amid accusations of fraud.
Security forces fired tear gas to disperse protesters. There were also unconfirmed reports that they had used batons and rubber bullets.
Mr Rafsanjani was leading weekly prayers for the first time in two months. He appealed for the release of detained opposition protesters and an end to Iran's "crisis".
Among those attending the prayers was defeated opposition candidate Mir Hossein Mousavi (seated at centre). He has called for a re-run of Iran's presidential vote.
What are these?