An American soldier was fatally wounded in a small arms attack and later died in Baghdad late Thursday just after his patrol caught three Iraqis preparing to launch mortars from a truck.

The patrol opened fire on the truck, which ignited and set off the mortar rounds causing a series of explosions to rock the Iraqi capital, it said.

Soldiers arrested the three suspects but as they resumed their patrol a second band of insurgents attacked them with gunfire and rocket-propelled grenades, a US military spokesman said.

"One soldier was wounded in the attack and later died of his wounds," the spokesman said. Two suspects were arrested and taken in for questioning.

Another US soldier died in an incident that was not related to the violence that has claimed the lives of hundreds of other soldiers since the US-led invasion in March 2003, the military said on Friday.

"A 1st Cavalry Division soldier died in a non-battle related incident around 5:30 pm (1330 GMT) July 8," a statement said.

The cause of death was under investigation, the statement said without providing further details.

According to Pentagon figures published Thursday, 870 American soldiers died in Iraq since the start of combat operations on March 19, 2003. Of them, 647 were due to hostile circumstances.

Meanwhile, two truck drivers, believed to be Turkish, were killed Thursday when their convoy was attacked by unknown gunmen near this insurgent bastion north of Baghdad.

The bodies of the drivers was wrapped in white sheets and blankets, and loaded up in an Iraqi police pickup truck in Samarra, an AFP photographer on the scene said.

"They are Turkish and they came into Iraq today through the north," said Major Nasser al-Samarrai as he showed what appeared to be Turkish passports.

"We are taking them to the hospital's morgue now and we will be contacting their embassy shortly."

The trucks had Turkish registration plates.

The red fuel tanker, part of an eight-truck convoy that the slain drivers were in, appeared to have skidded off the highway connecting the north with Baghdad, crashing into an open field nearby.

One of the other drivers in the convoy, giving his name as Ayub, said he saw armed men in a black car spray the fuel tanker with bullets.

Attacks on convoys are common on Iraq's highways and they have claimed the lives of dozens of foreign workers.