Clashes erupt for second day in Iran, four protesters killed

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TEHRAN, Dec 27 (Reuters): Security forces fired tear gas to disperse opposition supporters in central Tehran Sunday, during a second day of clashes in the Iranian capital, an opposition website said.
The Jaras website said protesters set one police motorbike on fire in downtown Tehran. A plume of black smoke could be seen above the center of the city, it added, as police blocked streets in the area and clashes intensified.
"There are sporadic clashes in different parts of downtown Tehran, including the Khark street ... There is a mass presence of protesters. Their number is increasing," Jaras said in a report that could not immediately be independently verified.
The authorities have warned the pro-reform opposition against using a two-day major Shi'ite Muslim religious mourning ritual on December 26-27 to revive protests against the clerical establishment, six months after June's disputed election.
Police helicopters were seen flying overhead in Tehran.
In a show of defiance, the moderate opposition had urged its supporters to gather in central Tehran Sunday morning.
Meanwhile, Iranian security forces opened fire on anti-government protesters in the capital Sunday, killing at least four people and injuring two others, opposition Websites and witnesses said, in the fiercest clashes in months.
Authorities had warned of a harsh crackdown should opposition supporters hold rallies coinciding with Sunday's religious observances marking the 7th Century death in battle of one of Shiite Islam's most beloved saints.
The clashes marked the bloodiest confrontation between protesters and security forces since the height of the unrest in the weeks after June's disputed presidential election.
Reporters from foreign media organisations were barred from covering the demonstrations and the reports of deaths could not be independently confirmed.
Defying the warnings, thousands of protesters made their way to Tehran's central Engelab Street, or Revolution Street, chanting "death to the dictator," a reference to hard-line President Mahmoud Ahmadinejad. The opposition says Ahmadinejad won the June election through massive vote fraud and that its leader, Mir Hossein Mousavi, was the true winner.
After failing to disperse the crowds with tear gas, charges by baton-wielding officers and warning shots fired into the air, security forces opened fire directly at protesters, killing at least three people, said witnesses and the pro-reform Web site Rah-e-Sabz.