A car bomb has killed at least three people and wounded at least nine others in Baghdad.
The blast was reported late Friday. Earlier in the day, the U.S. military said five Marines were killed Thursday by a roadside bomb blast in western Iraq's Anbar province.
The military said the Marines were conducting combat operations near the volatile town of Haqlaniyah when they were killed.
Also Friday, U.S. officials said they are launching a criminal investigation into the killing of two army officers at a base north of Baghdad on Tuesday. Officials first reported they had been killed by mortar fire, but say an investigation has ruled that out.
Separately, Iraqi officials say gunmen shot dead two senior police officials in Kirkuk and two police officers in Basra.
And at least 16 bodies of people who appeared to have been killed execution-style were found in western Iraq.