Tens of thousands of supporters of radical Shiite cleric Moqtada al-Sadr responded to his call for mass demonstrations in the Shiite holy city of Najaf Monday. From Baghdad, VOA's Margaret Besheer has more.

Followers of radical anti-U.S. cleric Muqtada al-Sadr march through the holy city of Najaf, 09 Apr 2007

The demonstrators gathered in the southern city of Najaf on the fourth anniversary of the fall of Baghdad to U.S.-led forces.

The crowd chanted, "Get out occupier!" and waved Iraqi flags and banners saying "Down with Bush, Down with America."

They marched from the nearby city of Kufa to Najaf. Many people came by bus from other cities, including Baghdad.

Security was tight with Iraqi police and soldiers guarding checkpoints near the city. Across Iraq, a 24-hour ban on all vehicles went into effect at 5 o'clock Monday morning.

Anti-American cleric Moqtada al-Sadr, whose Mehdi Army fought coalition forces in Najaf in 2004, called on supporters to protest the continued presence of U.S. and foreign forces in Iraq.

By midday the cleric had not made an appearance at the rally. U.S. officials say Moqtada al-Sadr has gone to Iran to escape the current security crackdown, but his aides deny it, saying the cleric is in Iraq.

In his place, Iraqi parliamentarian and Sadr spokesman Nasir Rubai told the crowd that the invading enemy which has invaded our land is now targeting the dignity of the Iraqi people. He said after four years, there are hundreds of thousands of dead and injured Iraqis.

Also addressing the rally was Shiite cleric Abdul Hadi al Muhammad Awi, who called for the withdrawal of "the last American soldier" and said the continued presence of any kind of military base in this Islamic country would be unacceptable.