BAGHDAD -- A U.S. military convoy opened fire on a column of cars Sunday morning, killing at least two Iraqi civilians in southern Iraq and igniting a new round of anger over the apparent loss of innocent life.
Key details were murky -- including whether the military convoy fired as it approached the cars from behind, as local police contended. The number of fatalities was also unclear.
Police charged that the shootings were unprovoked and said six people, including two Iraqi policemen, died in a barrage of bullets.
The incident occurred on a day when U.S. officials announced that attacks in Iraq were at their lowest levels in nearly two years.
The first word of the incident came from an apology jointly issued late Sunday by the U.S. Embassy and the U.S. military, but the statement referred to only two deaths and four injuries.
A U.S. military spokesman said the incident was under investigation, and declined to release details. The military would confirm only that the deaths were the result of "a shooting incident" near Samawa, the capital of Muthanna province, located 160 miles south of Baghdad.
"The shooting was heavy," said 1st Lt. Hussam Mohammed of the Samawa police department.
"They shot from behind," he said. "We do not have anything in our report for any reason that would justify the shooting."
Five cars were damaged during the shooting, which occurred around 10 a.m. Sunday, Mohammed said.
"We profoundly regret when any innocent civilian is killed or injured," the U.S. statement said. It said the families of those killed, as well as those injured, would be "properly cared for."
Local government officials, who chided military forces for what they deemed as unnecessary force, denounced the shooting incident.
The governor of Muthanna province, Ahmed Marzook al-Salal, condemned the incident and demanded that the U.S. government provide compensation to the families.
Meanwhile, U.S. officials announced Sunday that attacks in Iraq were at their lowest levels since January 2006 and are 55 percent lower since the surge of U.S. troops began in June.
During the same period, civilian deaths throughout Iraq declined 60 percent, said Rear Adm. Greg Smith, spokesman for the U.S.-led coalition forces in Iraq. In Baghdad, civilian fatalities decreased by 60 percent.
"However, we are still in a fight with an enemy that has both the will and capacity to conduct barbaric attacks," Smith said, "and unfortunately we are reminded of this daily."
A spate of violence on Sunday underscored the point, with dozens of casualties reported in Baghdad and elsewhere.
In Baghdad's Karrada neighborhood, nine civilians died and 20 others were injured when a car bomb exploded Sunday afternoon at a busy square. Police said the blast appeared to target the convoy of a deputy finance minister, who was not among the fatalities.
In Baqouba, north of Baghdad, three children died and seven other people were wounded when an improvised explosive device detonated near a park. In nearby al-Hashimiyat, two were also wounded by an IED.
In Tikrit, a police officer was killed and another injured by an IED that was being transported as evidence.
In Mosul, three civilians died and 16 people were hurt, including five policemen, when a suicide car bomb attacked a checkpoint.
A policeman in Basra was injured when gunmen attacked a police training center.
McClatchy special correspondent Qassim Zein contributed from Najaf.