There were numerous conflicting statements about whether the building was a mosque.
BAGHDAD, Iraq -- The walls were crumbling and there were signs of disarray in the compound clearly used as a gathering place for prayer. Religious posters lined the walls, along with banners denouncing the attack.
Fresh television footage showed the aftermath of a U.S.-Iraqi military assault that killed at least 16 people in a complex the Americans said housed a kidnapping cell -- but which many Iraqis said was simply a Shiite mosque filled with worshippers at evening prayers.
Shiite politicians raged at the United States and halted negotiations on a new government following Sunday's raid in northeast Baghdad. A unity government involving Shiites, Sunnis and Kurds is a benchmark for American hopes of starting to withdraw troops this summer.
The criticism will also probably make it harder for Shiite politicians to restrain their more angry followers as sectarian violence boils over. Fresh violence erupted in the north, with 40 killed in a suicide bombing. At least 151 Iraqis have been killed over the two-day period ending Monday.
There were numerous conflicting statements from Iraqis and the Americans about Sunday's raid. Iraqi police, Shiite militia officials and major politicians have all said the structure attacked was the al-Mustafa mosque. But the U.S. military said no mosques were entered and that the raid targeted a building used by "insurgents responsible for kidnapping and execution activities."
Lt. Gen. Peter Chiarelli, deputy commander in Iraq, and Maj. Gen. J.D. Thurman, commander of the 4th Infantry Division, which is in control of Baghdad, told reporters early Tuesday 25 U.S. forces were in a backup role to 50 Iraqi Special Operations troops.
The mission, the generals said, was developed by the Iraqis on their intelligence that an Iraqi dental technician, kidnapped 12 hours earlier for ransom, was being held in what they called an office complex.
"It's important to remember we had an Iraqi unit with us, an Iraqi unit of 50 folks and they told us point blank that this was not a mosque," Chiarelli said. "It's not Mustafa mosque. Mustafa mosque is located six blocks north on our maps of this location."
Associated Press reporters who visited the scene of the raid identified it as a neighborhood Shiite mosque complex.
In an earlier statement, the military said the building had been under U.S. observation for some time.
The statement said gunmen opened fire as Iraqi special operations troops closed in. It said the troops then killed 16 insurgents and wounded three "during a house-to-house search," detained 18 men, found a significant weapons cache and freed the hostage.
"In our observation of the place and the activities that were going on, it's difficult for us to consider this a place of prayer," said Lt. Col. Barry Johnson, a U.S. military spokesman.
Iraqi police said gunmen fired on the U.S.-Iraqi patrol from a position in the neighborhood but not from the mosque.
Police and representatives of Muqtada al-Sadr, the radical Shiite cleric who holds great sway among poor Shiites in eastern Baghdad, said all those killed were in the complex for evening prayers and none was a gunman. Police put the death toll at 17 -- seven members of al-Sadr's militia, seven civilians and three Shiite political activists.
Video from Sunday night showed male bodies with gunshot wounds on the floor of what was said by the cameraman to be the imam's living quarters, attached to mosque itself. The compound, once used by Saddam Hussein's government, consists of a political party office, the mosque and quarters for the imam.
The video also showed 5.56 mm shell casings scattered on the floor. U.S. forces use that caliber ammunition and have provided it to Iraqi special operations troops.
But Chiarelli said someone had gone into the scene of the raid to make it look as though there had been an assault without cause.
"After the fact someone went in and made the scene look different than it was," Chiarelli said.
Neither general would say who might have carried out such a charade. Nor would they say what they had learned about the men detained in the operation.
Interior Minister Bayan Jabr angrily rejected the U.S. account and demanded a "clear explanation."
"Entering the Mustafa Shiite mosque and killing worshippers was unjustified and a horrible violation from my point of view," Jabr said on the Al-Arabiya TV network. "Innocent people inside the mosque offering prayer at sunset were killed."
President Jalal Talabani, a Kurd, said he called U.S. Ambassador Zalmay Khalilzad and that they decided to form an Iraqi-U.S. committee to investigate.
"I will personally supervise, and we will learn who was responsible. Those who are behind this attack must be brought to the justice and punished," Talabani said.
The United Iraqi Alliance, the largest Shiite bloc in parliament, canceled Monday's session of negotiations to form a new government because of the raid, said lawmaker Jawad al-Maliki.
The Baghdad governor said he cut ties with U.S. forces and diplomats. And all 37 members of the Baghdad provincial council suspended cooperation with the United States in reconstruction projects planned for the remainder of the year, as well as political and security coordination, said council chairman Moeen al-Khadimi.
He said the local government would try to rely instead on the budget allocated to it by the Finance Ministry and on donor countries.
The U.S. statement describing the kidnappers and killers they were targeting as "insurgents" was unusual because the operation took place at a Shiite facility. The insurgents who have been carrying out nearly daily bombings are Sunnis, while those believed responsible for execution-style slayings are primarily Shiite militias or death squads working inside the Shiite-dominated Interior Ministry, which runs the police.
"We don't know who they were," Chiarelli said. "They were terrorists, insurgents, you can call them what you will."
Monday's major suicide bombing took place at an Iraqi army recruiting office near the gate of a U.S.-Iraq military base about 20 miles east of Tal Afar, an ancient city not far from the Syrian border.
The bomber, wearing an explosives vest, killed at least 40 Iraqis and wounding 30 others, the Iraqi Defense Ministry said.
In yet one more gruesome discovery -- a nearly daily occurrence since the Feb. 22 bombing of a Shiite shrine in Samarra -- 29 more bodies were found, nine with nooses around their necks.
The country's senior Shiite politician, Abdul-Aziz al-Hakim, told CNN the bombing made it more difficult to control the streets.
"For three years we've been burying the slaughtering, killing, explosions, attacking of our scholars, our mosques, our facilities, our pilgrims, our barbers, our bakers, our innocents," al-Hakim said. "We are always speaking to people to restrain themselves and calm down."