Insurgents in Iraq have killed at least eight people in a series of attacks against American soldiers, Iraqi police and civilians working for the U.S.-led coalition.

In the most recent attack, officials say gunmen fired from a vehicle at a police checkpoint between the towns of Fallujah and Ramadi, in the tense region west of Baghdad. At least two policemen were killed and three were wounded in Thursday's attack.

Hours earlier, U.S. military officials say two American soldiers were killed and one seriously wounded in a mortar attack late Wednesday in the town of Baquba. The incident brought the U.S. military death toll since the start of the war in Iraq to 505.

Also late Wednesday, insurgents opened fire on a minibus carrying Iraqi women home from work at a U.S. base near Fallujah. Iraqi police said at least three women and the driver of the vehicle were killed and six other women were wounded in that attack.

Meanwhile, Spanish officials say the head of security for a Spanish military brigade in Iraq was shot and seriously wounded in the southern town of Diwaniyah.