A reformist website said Iranian riot police fired tear gas to disperse opposition supporters who used a Shiite religious mourning ceremony on Saturday to try to revive anti-government protests in the Islamic Republic.
"Police are firing tear gas to disperse a huge crowd in Imam Hossein square … but people are resisting and chanting slogans against the government," the Jaras website reported.
The same website earlier on Saturday said security forces "fiercely" confronted opposition backers in different parts of the capital.
"Police sought to disperse about 200 to 300 people who wanted to gather in Enghelab square. They beat up some and detained several people," an AFP correspondent said, adding that demonstrators were shouting "death to the dictator."
Small groups of people also gathered around the nearby Tehran university — a hotbed of anti-government protests — with some shouting slogans and at least two people were seen arrested.
"Riot police are fiercely confronting the opposition supporters in different parts of Tehran … they (the police) are also breaking windows of cars passing the area," Jaras said.
Iran police chief Esmail Ahmadi Moghaddam issued a fresh warning Saturday against attempts to use Shiite processions marking the Ashura rituals as a means to stage fresh protests against the government of President Mahmoud Ahmadinejad.
"Police will severely crack down on rioters. We will identify and arrest riot leaders," he was quoted as saying by the official ISNA news agency.
Six months after a disputed election plunged Iran into political turmoil, tension has again mounted in the major oil producer after death a week ago of leading dissident cleric Grand Ayatollah Hossein Ali Montazeri at the age of 87.
Montazeri’s death occurred in the tense run-up to Ashura on Dec. 27, an important Shiite religious commemoration that offers the opposition another opportunity to show its strength. That day coincides with the seventh day of mourning for Montazeri, when more memorial services are usually held.
On Ashura, Shiite Muslims commemorate the 7th century death of Imam Hossein, a grandson of the Prophet Mohammad.
Religious ceremonies are also traditionally held across Iran on the day before Ashura, called Tasoua.