US soldiers have killed three Iraqis, including an 11-year-old boy, after mistaking the gunfire of customers testing weapons for an attack in Baghdad.
Four people were also wounded in the shootings at Baghdad's gun market.
In Iraq, it is legal for a family to own one gun for self-defence. That weapon is usually an AK-47 assault rifle.
The gun market, however, is illegal and has been raided repeatedly by American soldiers, who have tried to close it down.
The incident began when a group of Iraqis were testing a gun in the market by firing it in the air, said Major Ali Rykan of the Iraqi police.
As they shot, four armoured cars passed by, Major Rykan said.
At least two American soldiers opened fire on the market, killing the three, said Major Rykan and Hashem Naim Mohammed, a witness. His 11-year-old nephew, Akil Hussein Naim, was among the dead.