Iraqi authorities say at least 19 Iraqis - including 18 national guardsmen - have been killed in a suicide car bomb attack north of Baghdad.
The officials say the bomber targeted a bus carrying the guardsmen near the town of Balad.
In a separate attack, the U.S. military says four Iraqi policemen were killed and another wounded Sunday in the nearby town Samarra.
Meanwhile, U.S. military officials say two new brigade-sized military units of Iraqi and U.S. troops have been deployed in the northern city of Mosul, ahead of January 30th elections. A U.S. brigade consists of 2,000 to 4,000 troops.
Last month, the Pentagon ordered 12,000 more U.S. troops to Iraq to bolster security ahead of the polls. U.S. General John Abizaid said as many as 8,000 members of the new force would be deployed in Mosul.
Some information for this report provided by AFP and Reuters.