BAGHDAD — Two suicide bombers, one apparently armed with a grenade as well as an explosive vest, killed at least three people and wounded 17 as worshippers left a Shiite mosque after Friday prayers in the northwestern city of Tal Afar.

The explosions came on a day when the U.S. military and Iraqis were at odds over who was killed in a raid earlier this week, also in this country's restive north. The Americans and their Iraqi allies are pushing to take control of the region, where insurgent fighters are making a stand with their influence diminished in Baghdad and other areas.

The suicide bombers struck the Sheik Juwad mosque in Tal Afar, about 260 miles northwest of Baghdad.

The first bomber "threw a grenade on worshippers before he blew himself up," said the city's mayor, Maj. Gen. Najim Abdullah. A few minutes later, the second attacker ran toward people scrambling in the aftermath of the first explosion. "But police opened fire on him before he reached the people," the mayor said.

A police officer, who spoke on condition of anonymity because he was not authorized to release information, said the second attacker blew himself up without causing casualties.

The mayor said three people were killed and 17 wounded.

Earlier, the U.S. military said six insurgents were killed in raids in northern Iraq. But local police and an eyewitness said the dead included two women and four members of the local awakening council — the Sunni-dominated groups that abandoned al-Qaida last year and have allied with the Americans.

The differing accounts highlights the ongoing problems for the United States in trying to conduct a war in which the enemy is not always clear and tensions can arise easily.

The U.S. also faced complaints this month from its Sunni partners over the deaths of civilians in attacks both north and south of Baghdad.

The U.S. military said in a statement that it conducted raids in the Salahuddin province, north of Baghdad, late Wednesday and early Thursday. One target was an alleged al-Qaida leader in the area but it was unclear whether he had been killed or captured.

According to the military account released Thursday, troops at one spot returned fire from insurgents, killing two. They then called in air support, which killed another four militants. One civilian was wounded and evacuated for further care, while 15 suspected insurgents were detained. All those killed were "terrorists associated" with al-Qaida in Iraq, said Lt. Michael Street, a military spokesman.

An Iraqi police officer in the area, however, said Friday that a house belonging to a Sunni Arab and tribal leader was bombarded in a U.S. air strike, and that six family members died. The officer, who spoke on condition of anonymity because he was not authorized to release the information, said the bombing occurred about 33 miles southwest of Kirkuk and two of the victims were women.

A witness, who also declined to be identified for fear of retribution, told The Associated Press that among those taken into custody was a local tribal leader and head of the awakening council for the area. Funeral ceremonies for those killed were held Thursday, he said. He said five houses were bombed, in all.