TEHRAN // Iranian security forces fired tear gas to scatter thousands of people marching on a Tehran square in a banned rally on Monday inspired by popular uprisings in Egypt and Tunisia, a witness said.
"There are thousands of people marching, not chanting slogans. Security forces fired tear gas to disperse them near Imam Hossein square," the witness said.
The march was a test of strength for the reformist opposition, which had not taken to the streets since December 2009, when eight people were killed. But Iranian security forces are still unlikely to hesitate to use any means to stop protests.
Large numbers of police and security forces wearing riot gear were stationed around the main squares of the capital and travelling in pairs on motorbikes around the city.
There were minor clashes at some points across the sprawling capital city of some 12 million people, witnesses said. Mobile telephone connections were down in the area of the protests.
"There were thousands of people walking towards Azadi Square. There were some scuffles. I saw smoke, but I am not sure if it was tear gas or not," another witness said.
The demonstrators marched down Enghelab and Azadi (Freedom) streets, leading to Azadi Square, a traditional rallying point for protests in central Tehran dominated by a huge white marble arch. Hundreds of marchers also gathered in the cities of Isfahan and Shiraz, witnesses said.
But security forces surrounded the houses of opposition leaders Mirhossein Mousavi and Mehdi Karroubi preventing them and Mr Mousavi's wife, Zahra Rahnavard from joining the march, their websites said.
"Mirhossein Mousavi and Zahra Rahnavard are still trying to leave their house and join the protests but security forces are preventing them. Security forces have even threatened Mousavi's guards to not allow them to leave the house by any means," the Mousavis' Kalame website said.
Mr Mousavi and Mr Karroubi took advantage of official Iranian backing for the huge street protests in Egypt and Tunisia to call their own demonstrations in solidarity, but authorities refused their request.
The opposition nevertheless renewed the call for the rally. Iranian authorities have warned the opposition to avoid creating a "security crisis" by reviving protests that erupted after the vote, the biggest unrest in Iran since the 1979 revolution.
The Iranian supreme leader, Ayatollah Ali Khamenei, called the uprisings in Egypt and Tunisia an "Islamic awakening", akin to the 1979 revolution that overthrew the US-backed shah of Iran.
But the opposition see the unrest as being more similar to their own protests after the election of June 2009, which they say was rigged in favour of President Mahmoud Ahmadinejad.
The Revolutionary Guards, fiercely loyal to Mr Khamenei, put down the 2009 protests. Two people were hanged and scores of opposition supporters jailed.
The Turkish president, Abdullah Gul, on a visit to Tehran, called on Middle Eastern governments to listen to the demands of their people, although he did not refer to Iran.
"We see that sometimes when the leaders and heads of countries do not pay attention to the nations' demands, the people themselves take action to achieve their demands," Mr Gul told a news conference alongside Mr Ahmadinejad.
Any use of heavy force to stop the marches in Iran during Mr Gul's visit could be an embarrassment for Turkey.
However, Ankara, officially an ally of the West, was one of the first governments to congratulate Mr Ahmadinejad on his re-election in 2009 and is seeking to triple the volume of trade with its neighbour despite UN, U.S. and EU sanctions imposed on Iranc over its disputed nuclear activity.
Iranian authorities deny doctoring the 2009 election results and accuse opposition leaders of being part of a Western plot to overthrow the Islamic system.