A suicide car bomber attacked an Iraqi police station in the western city of Ramadi, killing 11 people including four policemen, the US military said on Thursday.
Wednesday's attack also wounded 21 people, a spokesman said.
Iraqi medical and security sources in the city, a hotbed of Sunni insurgents, said the police station was severely damaged in the blast.
They said the local police chief was among those killed, but that was not confirmed in the US statement.
Iraqi security forces are a constant target for insurgent fighters trying to undercut the Shiite-dominated unity government of Prime Minister Nuri al-Maliki.