TEHRAN, IRAN - Dozens of people on motorcycles surrounded the office of Iranian opposition leader Mir Hossein Mousavi Tuesday and prevented him from stepping out, a source close to him and his website reported.

All the entrances of the Academy of Fine Arts, located in central Tehran and which Mousavi heads, were surrounded by motorcyclists, a source working inside the building told AFP.

Mousavi's website Kaleme.com also reported the incident, saying the opponents were shouting slogans against him.

"The purpose of blocking the eastern and the western gate is to prevent him from getting out," the source said, adding there was "no fight or confrontation."

"They allowed other employees to leave. We have asked the police to comeand disperse them but so far not many policemen have arrived to disperse the crowd."

Kaleme.com said the crowd of 30 to 40 motorcyclists in plain-clothes had surrounded the building where Mousavi, who has outraged the country's hardliners by challenging the re-election of President Mahmoud Ahmadinejad, works.

It said Mousavi had approached the motorcyclists when he wanted to leave the building and said to them, "You have a task. Carry out your mission... hit me, kill me or threaten me."

The source from inside the building said Mousavi continued to be in the office.

Meanwhile, a group of hardline vigilantes attacked Mousavi's wife during anti-government protests in universities on the Student Day commemoration Monday, an opposition website reported on Tuesday.

Mousavi's wife Zahra Rahnavard, who is a professor at Tehran University, was approached by a group of women and insulted on Monday as she was about to attend the Student Day ceremony, Mowjcamp.com reported quoting a witness.

"Security helped Rahnavard to leave the campus, but these people followed her and pepper-sprayed her from a close distance," it said, identifying her attackers as "militia forces" - an allusion to hardline Islamist Basij.

Rahnavard was hurt in the eyes and lungs, it said.

Fresh protests erupted in Iran on Monday against President Mahmoud Ahmadinejad, whom the opposition charges was re-elected in a massively rigged June 12 poll.

The protesters clashed with the police and members of the Basij, which have had a key role in suppressing street protests since the dispute over Ahmadinejad's re-election erupted. --AFP