Iranian anti-government protesters are reported to have clashed with security forces in the capital, Tehran, on Tuesday. The protesters were demonstrating against the reported arrest of two opposition leaders, Mir Hossein Mousavi and Mehdi Karroubi.
Iranian opposition website kalemi.com says security forces were deployed in large numbers and fired tear gas at protesters near Tehran University.
Those protesters turned out to demand the release of opposition leaders Mousavi and Karroubi, who have reportedly been arrested and jailed along with their wives.
The United States on Monday called for their release, but Iran’s administration has yet to confirm the arrest.
Speaking Tuesday, Iranian Foreign Ministry spokesman Ramin Mehmanparast told reporters that the whereabouts of the opposition leaders is a domestic matter.
He said no country has the right to interfere in Iran’s internal issues.
Baqer Moin, a Britain-based writer and journalist and an expert on Iran, says the whereabouts of Mousavi and Karroubi is unclear, and that may be an intentional move by the government.
"It may show that there is not yet a clear decision within the establishment whether to arrest them or not, or at the same time it may be an attempt to test the water to see how people are receiving their arrest," said Moin.
Mousavi and Karroubi were put under house arrest in mid-February after calling for their supporters to march in support of revolts in Egypt and Tunisia.
That demonstration, which was held on February 14, was the first sign in more than a year that Iran’s opposition movement is still intact.
The opposition Green Movement sprang up following the disputed 2009 presidential election, but a severe crackdown by Iranian authorities silenced the movement - at least until last month.
Moin says hardliners in Iran want Mousavi and Karroubi, the leaders of that movement, out of the political picture.
"Both of them are very important personalities, and their names are carrying a lot of weight among their supporters within Iran and also outside Iran among the Iranians," said Moin.
The Middle East and North Africa have been hit by a wave of unrest in recent months. A revolt in Tunisia overthrew the country’s longtime leader, Zine El Abidine Ben Ali, and Egyptian President Hosni Mubarak met the same fate only a month later.
Now a number of other leaders in the region are facing challenges to their authority.
Sir Richard Dalton, an Iran expert with the London-based research group Chatham House, says the leaders of Iran’s opposition are not looking for an overhaul of the Islamic Republic.
"At the moment, there is no leader inside the country that is a symbol of that call for fundamental change," he said. "If there were, the Iranian authorities would move very quickly to silence him or her, but the fact is that in the long term, who knows, leaders may emerge both inside and outside the country, but it will be long struggle."
But Iran’s government is suffering a wave of criticism, both internal and international, over human rights abuses. And with a continued push led by the United States for tighter sanctions, Iran’s economy is also suffering.
Cuts in state subsidies have led to inflation, and unemployment is high.
Still, Dalton says he thinks it is unlikely that Iran’s government will be confronted with an upheaval like that in nearby countries, unless it unleashes a violent crackdown on the population.
“If that does not happen, then I would expect the progress of opposition in Iran to be long and slow rather than short and dramatic," he said. "I am not expecting, therefore, an early revolution along Egyptian or Tunisian lines in Iran.”
Two people were killed in the February 14 demonstration, and at least 150 people were arrested.
Officials in Iran have branded anyone who supports Mousavi and Karroubi as "anti-revolutionary."