In a separate incident Friday, two US soldiers on patrol south of Baghdad were killed by a homemade bomb, a military spokesman said. Three others were injured in the explosion and evacuated to a hospital.
Overnight, the US military bombed the sparsely populated southern edge of Baghdad to root out insurgents believed to be launching mortar shells and rockets, hours after a US military helicopter was shot down west of the capital, killing one soldier.
Soon after the helicopter crashed Friday, the military said attackers posing as journalists fired assault weapons and rocket-propelled grenades at US paratroopers guarding the burning aircraft.
But there was confusion, because Reuters news agency reported that US troops fired at its team at the scene and the military later detained three.
"Our guys are still in detention, and we still haven't been informed of any specific accusations against them," said Andrew Marshall, Reuters' bureau chief in Baghdad.
Elsewhere, insurgents attacked an American tanker truck convoy, setting one ablaze.
Coalition forces raiding a Sunni Muslim mosque arrested 32 suspected non-Iraqi Arab insurgents and seized an arms cache. Hundreds of Iraqis protested outside the mosque after the raid.
In Baghdad, a military spokesman said the shelling of the Doura neighborhood was part of an offensive dubbed Operation Iron Grip. Residents said it appeared US fire was targeting fields in the neighborhood.
Bordered by date palm farms, the sparsely populated area once was home to a number of former officials in Saddam Hussein's government and is now the site of a US military base.
Operations like Iron Grip send "a very clear message to anybody who thinks that they can run around Baghdad without worrying about the consequences of firing [rocket-propelled grenades], firing mortars," US Army Brigadier General Mark Kimmitt told reporters Friday.
"There is a capability in the air that can quickly respond against anybody who would want to harm Iraqi citizens or coalition forces."
