Iraqi men flee the site of a roadside bomb after it exploded, in Baghdad, Iraq, 26 May 2008

Iraqi police say a suicide bomber on a motorcycle has killed six people in an attack on members of a U.S.-backed security force north of Baghdad.

Police say the bomber detonated his explosives Monday near the checkpoint manned by members of the Awakening Council in the town of Tarmiya. At least 16 people were wounded.

The Awakening Councils are funded by the United States and consist mostly of Sunni fighters who have joined U.S. soldiers in the battle against al-Qaida in Iraq. The groups have been a key factor in a recent drop in violence.

In a separate attack Monday, the U.S. military says a roadside bomb killed an America soldier and wounded two others in Salahuddin province.

At least 4,082 members of the U.S. military have died in Iraq since the war began in March 2003. Estimates of the number of Iraqis killed in the war range from the tens of thousands to the hundreds of thousands.

Some information for this report was provided by AFP an d AP.