A series of attacks north and west of Baghdad on Friday, including two suicide bombings, killed at least 28 people, mainly members of security forces, and wounded dozens, Iraqi officials said.
In the first of the attacks, a suicide bomber rammed his explosive-laden truck into a police brigade headquarters in the village of Injan, about 120 kilometres (75 miles) north of Baghdad, police officials said.
The explosion set off a firefight between other attackers and policemen. After it was over, nine police officers — including brigade commander Brig. Ragheb al-Omari and his assistant — were dead, the officials said.
Hours later, a suicide bomber detonated his explosive belt among mourners attending a funeral for Nasir al-Alawani, a leader in the anti-al-Qaida Sunni militia known also as Sahwa, who was killed a day earlier.
Police said nine mourners were killed and 25 were wounded in the attack in the city of Ramadi, 115 kilometres (70 miles) west of the Iraqi capital.
The Sahwa militia became prominent when its members joined U.S. troops in the fight against al-Qaida at the height of Iraq's bloodletting. Since then, it has been a target for Sunni insurgents who consider them traitors.
Since late December, Iraq's western cities have seen fierce clashes pitting government security forces and their tribal Sunni militia allies against al-Qaida-linked militants and other insurgent groups. The insurgents hold the city of Fallujah and parts of Anbar's provincial capital, Ramadi.
In other violence, police said gunmen sprayed an army checkpoint near the city of Samarra, north of Baghdad, killing four soldiers. They also abducted nine soldiers before leaving the area, police said.
And back-to-back car bombings killed three people and wounded 14 in Dibis, a town located near Kirkuk, 290 kilometres (180 miles) north of Baghdad.
Also, police said a roadside bomb hit a military convoy in the town of Beiji, north of Baghdad, killing one officer and two soldiers.
Medical officials confirmed the casualties from Friday's attacks. All officials spoke on condition of anonymity because they were not authorized to talk to the media.