In nearby Ramadi, 12 Marines were killed Tuesday in a seven-hour battle against insurgents including Syrian mercenaries, said Maj. Gen. James Mattis, 1st Marine Division commander. Three more Marines have been killed since Monday in Fallujah, the U.S. military said Wednesday.
Marine Lt. Col. Brennan Byrne said he ordered an attack on the Abdul-Aziz al-Samarrai mosque in Fallujah after his men came under fire from 30 to 40 insurgents inside and militants left the compound in an ambulance and shot at U.S. troops, the Associated Press reported.
"If they use the mosque as a military machine, then it's no longer a house of worship and we strike," he said.
U.S. forces dropped two 500-pound bombs and fired rockets at the outer wall of a mosque, where insurgents were hiding, according to Army Brig Gen. Mark Kimmitt, deputy director of operations for the U.S. military in Iraq.
Defense Secretary Donald Rumsfeld said Tuesday that the U.S. operation in Fallujah is aimed at capturing insurgents involved in attacks on Americans, including the ones who mutilated and burned the bodies of four civilian contractors last week.
The troops have pictures and names of those involved and were not attacking the town as a whole, Rumsfeld said, according to the AP.
Since Sunday, 32 Americans, two other coalition soldiers and more than 190 Iraqis have been killed in fighting in Iraq. The Iraqi total does not include those killed at the mosque, for which there is no definitive number.
Kimmitt has vowed to "destroy" the militia of radical Shiite cleric Muqtada al-Sadr, which has launched a separate wave of attacks against coalition troops in southern cities and Baghdad this week.
Al-Sadr issued a statement saying Iraq will turn into "another Vietnam" unless the United States transfers power to Iraqis not connected to the U.S.-led occupation.
Al-Sadr's "al-Mahdi Army" engaged in heavy gun battles with coalition forces in three southern cities Wednesday and for the first time in the north -- in the town of Baqouba, northeast of Baghdad. A U.S. helicopter was hit with small arms fire there, forcing it to land but not injuring the two crewmembers.
Overnight gun battles that killed 12 Iraqis in the southern city of Kut forced Ukrainian troops to withdraw from the city. Al-Sadr followers then entered the base, seized weapons stores and planted their flag in a nearby grain silo, according to the AP.
The al-Mahdi Army also has virtual control of Kufa and Karbala, where Iraqi police allow militiamen to move freely and act only to prevent looting.
Meanwhile, militiamen in Karbala clashed with Polish patrols, and a senior cleric in al-Sadr's office in the city was killed, the AP reported.
Al-Sadr, who is named in an arrest warrant for involvement in the brutal stabbing death of a rival Shiite cleric last year, still appears to be unpopular among most of Iraq's Shiite majority, but moderate Shiite clerics have not raised their voices strongly against the uprising.