A homicide bomber driving a dynamite-laden truck destroyed a key bridge Saturday on a highway used by the departing U.S. military, while separate attacks killed nine Iraqis, most of them security force members, police said.

There were no casualties in the blast that destroyed the bridge outside the city of Ramadi, which is about 70 miles west of Baghdad, said a local police officer. The highway is used heavily by the U.S. military to transport equipment out of the country. It is also a major roadway for civilian traffic.

The highway links Iraq to neighboring Syria and Jordan, where many Iraqis fled to escape sectarian violence.

Also Saturday, an attack on an Iraqi army convoy just outside of the city of Fallujah killed four Iraqi soldiers and wounded 14, said a police officer in the city, which is about 40 miles west of Baghdad.

Both officials spoke on condition of anonymity because they were not authorized to speak to journalists.

A U.S. military spokesman in Iraq's western Anbar province, where both Ramadi and Fallujah are located, confirmed Saturday's explosion on the highway bridge, which was close to two Iraqi military bases that host U.S. troops in the area.

Lt. Col. Curtis L. Hill said U.S. forces have "previously used the bridge," but he would not say what impact its destruction might have on U.S. military convoys transporting equipment out of Iraq to meet President Obama's deadline for a complete pullout of combat troops by August 2010.

The Anbar provincial police commander, Maj. Gen. Tariq Yousif Mohammed, told The Associated Press that he believed the blast was aimed at Iraqis. Traffic in and around Ramadi was backed up after the early morning explosion.

"I don't think the Americans were targeted by the blast," he said.

Western Anbar province was once a hotbed of Iraq's Sunni-dominated insurgency and the scene of some of the most intense U.S. fighting with militants. Violence subsided significantly after local tribes decided to align themselves with U.S. forces instead of Al Qaeda.

Attacks have not been halted entirely. Last Sunday, 19 people were killed in a spate of coordinated car bombings across Ramadi, Anbar's provincial capital, sparking fears of a reinvigorated insurgency that could destabilize Iraq before January's crucial parliamentary elections.

Elsewhere in Iraq, violence has intensified. The northern cities of Mosul and Kirkuk have recently been hit by horrific attacks targeting ethnic minorities and Iraqi security forces.

On Saturday, attackers threw hand grenades at an Iraqi army patrol near Kirkuk, 180 miles north of Baghdad, killing two civilians and wounding two others, a police official in the oil-rich city said.

In Mosul, 225 miles northwest of Baghdad, 2 policemen and one civilian were killed Saturday in three unrelated incidents, police said, speaking on condition of anonymity because they were not authorized to talk to the media.

Meanwhile, Britain's Home office said Saturday that only 10 of about 40 Iraqis who failed to get asylum in the U.K. and were sent back to Iraq were allowed to remain in the country after landing in Baghdad on Thursday.

There is an official agreement between the two countries to send those citizens who fail to get asylum in the U.K. back to Iraq.

An official at Baghdad airport denied Britain's claim that Iraq denied entry to some of the deportees, saying the roughly 30 passengers who returned to the U.K. were minority Kurds who were too afraid to remain in Iraq. The 10 Iraqis who remained were Arabs, he said, speaking on condition of anonymity because he was not authorized to talk to the media.