BAGHDAD, Iraq - A suicide bomber detonated a car packed with explosives next to a U.S. convoy on Baghdad's dangerous airport road today, and several casualties were seen lying next to a damaged vehicle, witnesses and authorities said.

In the northern town of Beiji, a car bomb exploded near a U.S. patrol today, killing four Iraqi civilians and injuring 19 people, two of them American soldiers, the military said. Another soldier from the 1st Infantry Division was wounded when insurgents fired a rocket-propelled grenade at a tank south of Beiji.

The attacks came as the military announced that a U.S. Army soldier died from injuries suffered after a roadside bomb exploded late Monday next to his patrol north of Baghdad, bringing to 134 the number of American troops killed in Iraq this month, according to an unofficial count.

This makes November the deadliest month for the U.S. military since last April when 135 troops died. Fierce fighting in Fallujah and insurgents' counterattacks elsewhere in Iraq have fueled the high death toll this month.

Amid the violence, interim Prime Minister Ayad Allawi prepared to travel to Jordan to meet with Iraqis living outside the country to encourage them to take part in the Jan. 30 election in a bid to take support away from the insurgency.

In the suicide attack, police Capt. Talib al-Alawani said a bomber drove his car into a U.S. convoy on the airport road, scene of near daily attacks against U.S. military and Western targets. The U.S. command confirmed that the attack occurred but had no further details.

Several casualties were seen lying next to a damaged vehicle, according to an eyewitness who arrived on the scene before troops sealed off the stretch of road where the blast occurred. A military ambulance drove up minutes later to evacuate the casualties.

The highway, which multinational troops use daily to commute between the huge military base at the airport and Baghdad's center, is considered one of the most dangerous roads in Iraq. The British Embassy announced Monday that its staff would no longer be permitted to travel on the road.

In Beiji, a U.S. military statement did not give the condition of the wounded nor specify whether the car bomb was a suicide attack.

U.S. troops backed by tanks and helicopter gunships launched a series of attacks on parts of Beiji earlier this month to try to root out insurgents from the town, located on the major supply route from Baghdad to the north.

On Monday, 13 Marines were wounded in a mortar south of Baghdad, the military said. No further details were released.

Military offensives in Fallujah and elsewhere have made November the second deadliest month for U.S. troops since the March 2003 invasion, with at least 134 American dead.

The Pentagon, meanwhile, said Monday the U.S. military death toll in Iraq since the U.S.-led invasion in March 2003 stands at 1,251. That is up 21 since the Pentagon last reported a total on Nov. 24.