Militants killed at least 22 members of the security forces in Iraq on Tuesday, mostly in attacks on police and military checkpoints, with the western Anbar province bearing the brunt of the violence, sources said.
No group immediately claimed responsibility for the suicide and gun attacks, but Sunni Muslim insurgents, including al Qaeda, have regularly targeted security personnel and others working for the Shi'ite-led government.
At least 60 members of the security forces were also wounded in the attacks, the sources said.
In the town of Rutba, 360 km (225 miles) west of Baghdad, a suicide bomber driving a car packed with explosives blew himself up near a police checkpoint killing at least five, while gunmen launched a series of attacks against police checkpoints in the town killing at least four, police sources said.
In the west of Ramadi, gunmen in vehicles attacked police and army checkpoints along the main highway that links Baghdad to Jordan and Syria, killing at least seven, police said, adding that clashes were still continuing.
A suicide bomber driving a tanker truck packed with explosives attacked a police checkpoint in the town of Jurf al-Sakhar, about 60 km (40 miles) south of Baghdad, killing four, police sources said.
In a separate incident in Mosul, a suicide bomber driving a vehicle packed with explosives detonated the car near a military checkpoint in the south of the city, killing at least two, police and medical sources said.
Mosul, capital of the predominantly Sunni province of Nineveh, is a stronghold for Islamist insurgents who have been reinvigorated by the war in Syria and growing resentment of the government that came to power after the U.S.-led invasion in 2003.
The militants have accused the government of marginalising their minority sect since the overthrow of Sunni strongman Saddam Hussein.
Violence in Iraq, which had eased after reaching a peak in 2006-2007, when al Qaeda's Iraqi affiliate was forced underground, is now rising again, with more than 7,000 civilians killed this year, according to monitoring group Iraq Body Count.
The violence continued against civilians on Tuesday. In eastern Mosul, gunmen broke into a house and killed two men in front of the family, then blew up the house, police said.
In Baghdad's Sadr City neighbourhood, police found three handcuffed and blindfolded men shot execution-style in the head. Police said the bodies were taken to the central morgue.