There were no casualties in the Saturday morning blast that destroyed the bridge, said a police officer in the city of Ramadi, about 70 miles (125 kilometers) west of Baghdad. The highway is used heavily by the U.S. military to transport equipment out of the country. It is also a major roadway for local civilian traffic.
The highway links Iraq to neighboring Syria and Jordan, where many Iraqis fled 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 (65 kilometers) 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 the destruction of the highway bridge outside Ramadi.
Lt. Col. Curtis L. Hill said U.S. forces have "previously used the bridge," but he would not say what impact the destruction of the bridge might have on U.S. military convoys transporting equipment out of Iraq to meet President Barack 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. Rather it is targeting the Iraqis," he said.
