A car bomb has exploded outside a Shia mosque in Baghdad, killing 15 people and wounding 39, hospital officials said. 

The car exploded on Friday outside the al-Taf mosque in southwestern Baghdad.

An audiotape released Thursday and purportedly recorded by Abu Musab al-Zarqawi, took aim at the Shia community, accusing it of participating in the deadly November assault on Fallujah.

"The battle of Falluja removed the ugly mask of the damned 'Rafidha', whose hatred (for Sunnis) was manifested in this battle," the audiotape said.

"They participated in the military campaign for the battle against Fallujah with the blessing of the imam of infidelity and apostasy, Sistani," it added.

Police station stormed

Separately, a dozen armed fighters stormed a police station north of Baghdad on Friday and blew it up, police said. No one was hurt in the attack. 

Fighters burst into the station, which was nearly empty for Eid al-Adha, and placed explosives inside, said Iraqi police Captain Abd Allah al-Hiti. The blast destroyed the station in the centre of the town of Hit, about 165km northwest of Baghdad. 

Iraqi police and US-trained security forces have been frequent targets for fighters who consider them collaborators with the American forces.

PHOTO CAPTION

US troops secure the area where a car bomb. (AFP)