Gunmen killed a US soldier and wounded seven others in Iraq on Tuesday.

The attack with rocket-propelled grenades and small arms in the city of Falluja brought to three the number of US fatalities from hostilities in the past 24 hours.

The US Central Command said in a statement the gunmen apparently fired from a mosque in the city, 50 km west of Baghdad. US troops fired back, killing two of the attackers and capturing six.

A US Army Medevac helicopter was damaged during the exchange when a Bradley Fighting Vehicle accidentally struck it while manoeuvring into a firing position, the Central Command said. The Arabic news network al-Jazeera, however, said the attackers had shot down the helicopter.

It was the second attack reported from Falluja in recent days on US troops. Last Wednesday, US soldiers killed two Iraqis in retaliatory fire.

Two US soldiers were killed and four wounded in two separate Iraqi ambushes on Monday.

"These incidents tell us that there are still many challenges throughout Iraq that we have to deal with," Captain David Connolly told Reuters Television in Baghdad. "We will continue to fight pockets of resistance as well as criminal gangs."