Four Iraqis were killed today when a roadside bomb destroyed a car in the northern oil refining town of Baiji, police said.
Those killed were two women, a man and a child. The city, in the restive Sunni Muslim region north of Baghdad, has seen a sharp increase in violence over the past week.
Fifteen Iraqis died there yesterday when a suicide bomber rammed his car into a US patrol and troops opened fire.
Clashes between US-led troops and insurgents later erupted in several parts of Baiji prompting troops to seal off the oil refinery in the north of the city to protect it from attack.
Earlier, a car bomb detonated near a US military convoy in western Baghdad, killing two people. The explosion occurred near the Yarmouk police station as a US armoured vehicle was driving by. Five other people were wounded.
Violence has flared in the north in the ten days since US-led forces attacked Fallujah. US troops say they now control the city after killing hundreds of insurgents, although fighting has continued in parts of the city.