Armed pro-government demonstrators opened fire on the car of an Iranian opposition leader shattering its windows, his Web site reported Friday. Sahamnews said the shooting happened late Thursday while former presidential candidate Mahdi Karroubi was leaving a building in Qazvin, some 140 kilometers west of Teheran. The report added that some 500 people had been demonstrating outside the building where Karroubi had been staying for the past day. The site described the demonstrators as armed and said police were unable to disperse them. Karroubi ran in June's disputed elections that reformists say was won by Iranian President Mahmoud Ahmadinejad because of fraud. Unrest began immediately Ahmadinejad's re-election. Clashes between security forces and opposition supporters resumed late last month, killing at least eight people. The shooting against Karroubi, however, represents a rare armed attack on a leading opposition figure. In 1999, the pro-reform politician Saeed Hajjarian was shot in the face and paralyzed. The attack is an indication that the political turmoil rocking the country is possibly slipping out of the government's control. Karroubi's car was earlier attacked by a mob wielding bricks in late December, just days after a harsh crackdown on opposition protests. Last month's bloodshed was the worst since riots following the disputed June election. Since then death threats against opposition leaders have increased. In a pro-government demonstration in late December, protesters called for the execution of karroubi and his fellow opposition leader, Mir Hossein Mousavi. On Friday, the senior cleric Kazem Sedighi appeared to give a green light for people to take matters into their own hands against opposition figures if the authorities didn't. "I am concerned that people will lose patience if the legal apparatus does not conduct its affairs in a timely manner," he said at Friday prayers in the capital. Sedighi also claimed that some of the 500 protesters arrested around the Shiite holy day of Ashoura Dec. 27 were intoxicated. Also Friday, Iran's official IRNA news agency quoted Tehran's prosecutor as saying that authorities will soon release a German national and a Syrian reporter who were apparently among those detained during the protests. Teheran's prosecutor Abbas Jafari Dolatabadi said five of the protesters detained are going to stand trial next week are members of the armed opposition group MEK, or Mujahedeen Khalq. He said they would stand trial on charges of defying the clerical establishment and could face death under Iranian law. The group fought the Western-backed monarchy of Iran in the 1960s and the current Islamic establishment in the 1980s. It moved its base to Iraq soon after 1979 Islamic revolution. The United States lists MEK as a terrorist organization, it has provided the Americans with intelligence on Iran. The European Union removed it from its terror list this year. Opposition members have on several occasions since the June election poured into the streets to protest the results. The opposition says more than 80 protesters have been killed in the postelection crackdown, but the government puts the number of confirmed dead at less than 40.