Security forces have used batons and tear gas to disperse opposition supporters in the Iranian capital, Tehran, witnesses and state media say.
Unconfirmed reports said the authorities had also opened fire. It came as an officially backed demonstration was held to mark 30 years since the seizure of the US embassy. Thousands were present at the anti-American rally, about 1.5km (1 mile) from where opposition supporters gathered in Haft-e Tir square.Other groups turned out in other parts of the capital to voice their opposition to the regime.
'Attacked'
Many of the opposition demonstrators wore green scarves or bands, which have been used in repeated protests since Iran's disputed presidential elections in June. Opposition supporters say the elections were rigged to ensure the re-election of President Mahmoud Ahmadinejad.
Riot police and pro-government militiamen had packed the streets in the centre of the capital on Wednesday, after reformist leaders had urged their supporters to attend peaceful rallies at the former US embassy
A well-known activist who was among the opposition supporters, Habibullah Payman, told the BBC's Persian service that he and others had been attacked.
"
came in peace and with the usual slogan of supporting peace and asking for freedom," he said.
"I saw no sign of violence or agitation in the crowd... Yet, they were attacked violently."
Opposition supporters chanted "death to dictators", as small fires burned in the street. Security forces made a number of arrests, reports said.
http://news.bbc.co.uk/2/hi/middle_east/8341631.stm
Two differing protests in pictures below from the AP
http://www.msnbc.msn.com/id/33621954/ns/news-picture_stories/displaymode/1247/?beginSlide=1