A series of car bomb explosions have killed at least 33 people and injured 106 others in Iraq. The attackers targeted Shia neighborhoods, police checkpoints, and security forces across the country.

The deadliest attacks were bombs in three parked cars that went off in Taji, 20 kilometers north of Baghdad, killing 11people and wounding 24, Reuters reported.Two police officers were killed when a car bomb went off in the town of Balad Ruz, 90 kilometers northeast of the Iraqi capital.In Shula, northwestern Baghdad's Shia neighborhood, a suicide bomber detonated a car packed with explosives, killing one and injuring seven others, an Iraqi police source told AP.In a separate incident, an unidentified gunman killed an Iraqi police colonel in the Amel neighborhood south of the capital. The shootout was followed by a car bomb explosion, Al Jazeera reported.Bombings also reportedly targeted a police convoy and two police officers in Baquba, north of Baghdad, and in Kut, south of the capital.Iraqi militants often use explosives against security troops. The last large-scale attack was on September 26, when two roadside bombs killed five people near Hilla south of Baghdad, including a police lieutenant colonel and two other officers. The incident came the day after a series of insurgent attacks across central Iraq that left nine people dead.Residents run for cover as a bomb goes off during an attack in Baghdad September 30, 2012 (Reuters / Saad Shalash)Iraqi security personnel stand at the site of a bomb attack in Kut, September 30, 2012 (Reuters / Jaafer Abed)Iraqi security personnel stand at the site of a bomb attack in Kut, September 30, 2012 (Reuters / Jaafer Abed)Residents inspect the site of a bomb attack in the town of Taji, September 30, 2012 (Reuters / Saad Shalash)Residents look on as they stand at the site of a bomb blast in the town of Taji, September 30, 2012 (Reuters / Saad Shalash)Residents inspect the site of a bomb attack in the town of Taji, September 30, 2012 (Reuters / Saad Shalash)Iraqi policemen inspect the site of a car bomb in the Karrada district in central Baghdad on September 30, 2012 (AFP Photo / W.G. Dunlop)Iraqi men inspect the site of a car bomb in the Karrada district in central Baghdad on September 30, 2012 (AFP Photo / W.G. Dunlop)An Iraqi man walks past a damaged police car at the site of a car bomb in the Karrada district in central Baghdad on September 30, 2012 (AFP Photo / W.G. Dunlop)