Seven US troops have been killed in three roadside bombings near Baghdad, the military said, making October the bloodiest month for Americans in Iraq since January.

In the far west, where US marines say they have been fighting for months to stem a flow of foreign Arab fighters and funds from Syria, local doctors and tribal leaders accused American forces of killing about 40 civilians in an air strike.

The military said on Monday it knew of no civilian deaths and believed it had killed an al-Qaida leader targeted by precision bombing.

Two roadside bombings near Baghdad on Monday killed six soldiers and the military announced the death of a Marine, who was killed by a similar device near Falluja on Sunday.

That made October, which saw Iraqis vote for a constitution and put Saddam Hussein on trial, the worst month the Americans have suffered since January, when violence surged before a parliamentary election.

Sophisticated bombs

No details were available on the attacks, but US commanders have been voicing increasing concern at the power and sophistication of roadside bombs, the biggest killers of their troops.

Devices capable of penetrating armoured vehicles have become more common this year, based on technology US and British officials say has been introduced from Iran.

A week after the US death toll since the 2003 invasion passed the 2000 mark, it rose to 2025 with the deaths of four soldiers in an attack on a patrol near Yusufiya, just south of Baghdad, and two in a similar incident near Balad, 60km to the north of the capital.

Near the border city of Qaim on Monday, US aircraft bombed a house close to Karabila before dawn in what the military said was a precision strike on an al-Qaida leader.

A hospital doctor in the Iraqi town of Qaim said 40 people were killed and 20 wounded, many of them women and children, and a tribal leader said no armed groups were there.

Continued air strikes

A US military spokesman said the precision bombing in Karabila, close to Qaim, was meant to avoid civilian casualties.

"We believe the targeted terrorist leader was killed, but we cannot confirm that," Colonel David Lapan said.

"Civilian deaths cannot be verified and hospital officials frequently make such claims."

"The Americans started to bomb around Betha from after midnight (2100 GMT) until dawn," said a police officer, reached by telephone, who asked not to be named for his own security.

US marines have mounted several offensives in the area over the past few months.

US warplanes supported by ground forces had bombarded Hsaiba destroying six homes, Iraqi journalist Mahmud al-Rawi told Aljazeera.

Iraqi report

"While we were trying to attend to the wounded, US fighter planes began bombing the place again," al-Rawi said.

He told Aljazeera that the area had been cut off by US forces, who had blocked roads preventing people from leaving the village and going to al-Qaim.

Al-Rawi said US planes and Apache helicopters had pounded Hsaiba almost daily.

"They are turning this town into another Falluja," he said.

PHOTO CAPTION

US Marine sharpshooters on in the town of al-Qaim at the Iraqi-Syrian border, in western Iraq. (AFP)