At least four people were killed in a coordinated attack on a police headquarters in Iraq's northern central province of Salahudin on Monday, a provincial police source said.
The attack occurred in the city of Baiji, some 30 km north of provincial capital Tikrit. Gunmen set off a car bomb at the entrance of the headquarters, then, using assault rifles and hand grenades, broke into the compound and fought fierce clashes with the guards, the source told Xinhua on condition of anonymity.
"The first report said that a police officer, two policemen and an attacker were killed so far in the blast and the following clashes," the source said.
The toll could rise as ambulances and civilian cars evacuated the victims to different hospitals and medical centers in the city, he said.
Iraqi security forces sealed off the scene, while local authorities blocked the entrances of the town and imposed a curfew as reinforcement troops arrived and were deployed in the city, the source added.
Salahudin province is a Sunni-dominated province and Tikrit, some 170 km north of Baghdad, is the hometown of former president Saddam Hussein.
Iraq is witnessing its worst violence in recent years. According to the UN Assistance Mission for Iraq, 8,109 Iraqis were killed in the country from January to November this year.