BAGHDAD, Iraq — U.S. forces mistakenly fired on a civilian vehicle outside an American base in a city north of Baghdad today, killing three people, including a child, the military said.

In the shooting of the three civilians, a U.S. soldier thought the vehicle was moving erratically outside the base in Baqouba and fired warning shots, said Maj. Steven Warren, a U.S. spokesman.

"It was one of these regrettable, tragic incidents, Warren said.

Dr. Ahmed Fouad of the city morgue and police officials gave a higher death toll, saying five people returning from a relative's funeral had been killed, including three children.

Officials said the differing toll may have been a result of a car bomb that targeted U.S. Humvees in the same area, killing five civilians and wounded 12 bystanders in the town of Kanan outside of Baqouba. The blast was the latest in a series of attacks that have killed at least 145 Iraqi civilians in the last four days.

In the largely Shiite southern city of Basra, insurgents killed a Sunni cleric, Khalil Ibrahim, outside his home, police Capt. Mushtaq Talib said. Ibrahim was a member of the Association of Muslim Scholars, a group of influential Sunni clerics that has been sharply critical of the Shiite-led government.

Earlier today, U.S. forces left a house in the northern city of Mosul where eight suspected al-Qaida members died in a weekend gunfight, and the White House said it was "highly unlikely" that terrorist leader Abu Musab al-Zarqawi was among the dead.

During the intense gunbattle with suspected al-Qaida members in Mosul on Saturday, three insurgents detonated explosives and killed themselves to avoid capture, Iraqi officials said. Eleven Americans were wounded, the U.S. military said.

On Saturday, police Brig. Gen. Said Ahmed al-Jubouri said the raid was launched after a tip that top al-Qaida operatives, possibly including al-Zarqawi, were in the two-story house.

However, Trent Duffy, a White House spokesman, said Sunday that reports of al-Zarqawi's death were "highly unlikely and not credible."

In Baghdad, three people, including one police officer, were killed today by gunmen, police said. Another body was found in a southern district of the capital with a note saying the man had been killed by insurgents, morgue officials said.

Over the weekend, an American soldier near the capital and a Marine in the western town of Karmah were killed in separate insurgent attacks, the military said. A British soldier was also killed Sunday and four others wounded by a roadside bomb in Basra.

The U.S. military also said Sunday that 24 people — including another Marine and 15 civilians — were killed the day before in an ambush on a joint U.S.-Iraqi patrol in Haditha, west of Baghdad in the volatile Euphrates River valley.

The three American deaths brought to 2,094 the number of U.S. service members who have died since the war began in 2003, according to an Associated Press count.