Insurgents in Iraq detonated bombs around a police building in the city of Ramadi on Sunday before storming inside wearing belts of explosives.
The number of casualties is unclear, but one report says six people are dead and 14 others wounded.
There were also reports of hostages as security forces surrounded the building in the centre of the city.
A third car bomb went off in the city centre, and a fourth car bomb detonated near the police building a short while later.
The BBC reports two suicide bombers then blew themselves up inside the building before the insurgents moved in.
The fighting was continuing on Sunday afternoon.