At least eight people were killed and 27 injured Friday in two separate attacks in Iraq, police sources and the US army reported.
Two US soldiers and four Iraqi civilians were killed in a car bomb blast targeting a military patrol in the Jalawla area of eastern Baquba city, 57 km northeast of Baghdad.
Six US soldiers were injured, the army said in a statement.
The Iraqi police had said earlier that an additional 12 civilians were injured in the blast and that a US helicopter was seen landing to help the injured.
The US army statement said that one Iraqi policeman and two civilians were killed and two policemen and 22 civilians were injured, but those numbers could not be independently confirmed.
In a separate incident, an explosive device that detonated in a Baghdad market killed two people and injured nine others, Iraqi police sources said.
The blast caused severe damage to several shops in the market, located in Baghdad's southern al-Dawra area, the sources added.
Also on Friday, Iraqi and US forces arrested four suspected senior members of Al Qaeda during an air attack in the northeast province of Diyala, according to a security source.
Two of the men were arrested when a force from the Quick Response Department in Diyala waged a joint air attack with US troops, targeting an Al Qaeda stronghold in the Hamrien mountains in Khanaqin, department official Naif al-Tamimi said.
"In another air attack operation, forces arrested two other leaders in al-Mafraq neighbourhood in central Baaquba," he added.
Several of the group's senior leaders have been arrested or killed over the past few months, as Iraqi and US forces launched a major offensive against Al Qaeda suspects throughout the country.
Deadly attacks that left dozens of Iraqis killed in the past weeks have been described as acts of revenge by Al Qaeda.