US troops are cracking down on looters in Falluja
Gunmen have shot and killed another US soldier in Iraq - reportedly after approaching a checkpoint he was manning and asking for medical help.
A statement from US Central Command said the attack happened in the western town of al-Qaim, near the Syrian border, on Sunday night.
US troops returned fire, killing one assailant, and they captured another. But at least one more assailant fled the scene.
The US soldier was the third to be killed in Iraq in five days, in what appears to be an emerging pattern of local resistance in several parts of the country.
"Assailants pulled up to the checkpoint in a vehicle and requested help for a 'sick' person in the car. Two people armed with pistols then exited the vehicle and shot the soldier," the US military said.
There has also been more shooting in the flashpoint town of Falluja, about 50 kilometres (30 miles) west of Baghdad.
The Americans say they were fired upon from inside a mosque while conducting "aggressive" patrols.
Many local people say troops are being heavy-handed and they resent the American military presence, correspondents say.
Falluja has seen repeated attacks on US forces since clashes with the local population in April in which the Americans killed at least 15 people and injured dozens of others.
More than 3,000 US troops and dozens of tanks have been sent into Falluja - a mainly Sunni Muslim town.
Nearly 30 US troops have died in fighting or accidents since 1 May, when US President George W Bush declared the war in Iraq effectively over.
There were 85 attacks on US forces in May alone - almost triple the number of the previous month.