BAGHDAD , Iraq ( CNN ) -- Thousands of followers of radical Shiite cleric Muqtada al-Sadr rallied in Baghdad on Thursday to mark the sixth anniversary of the fall of Saddam Hussein 's regime . Demonstrators burn an American flag at a rally in Baghdad , Iraq , on Thursday . They rallied at Firdous Square , where Hussein 's statue was pulled down on April 9 , 2003 , shortly after the U.S. invasion of Iraq . The protesters carried Iraqi flags , religious banners and posters for al-Sadr . They chanted religious songs . Hazem al-Araji , a senior aide to the radical Shiite cleric , called on the Iraqi government to release all Sadrist detainees inside U.S. and Iraqi prisons . Watch rally fill Baghdad streets » . `` Everyone shout out loud and let all those who live inside the Black Zone and Bush , the damned , hear our voices and release the Sadrist detainees immediately , '' al-Araji said . He also called on President Obama to support Iraqis and remove U.S. troops from Iraq . One protester called on the `` occupation '' to get out of Iraq and , at his urging , the crowd chanted `` down , down America . '' Al-Araji also called on the protesters to shout out `` No no America , No no Israel , Yes yes Iraq . '' Iraqi security forces closed off the surrounding streets and a number of the bridges during the rally , which al-Sadr announced on March 21 .
They shout anti - U.S. rhetoric , chant religious songs . Thousands of supporters of President al - Sadr gather in historic buildings . Al - Sadr aide calls on Iraqi government to release all Sadrist prisoners .