BAGHDAD: A wave of car bombs in southern Iraq killed 20 people on Sunday as the country grapples with a spike in violence and prolonged political deadlock, sparking fears of all-out sectarian war. In all, seven vehicles rigged with explosives went off in five cities south of Baghdad during morning rush hour, leaving 56 people wounded in primarily Shiite Muslim areas of Iraq. No group immediately claimed responsibility for the attacks, but Sunni militant groups linked to Al-Qaeda frequently target Shiites, whom they regard as apostates, in coordinated attacks. Car bombs went off in Kut, Aziziyah, Mahmudiyah, Nasiriyah and Basra, officials said. In Kut, a car bomb exploded outside a restaurant in an industrial area packed with vehicle repair garages, killing seven people and wounding 15. Another car bomb in nearby Aziziyah in the town’s main marketplace and near a Shiite mosque killed five and wounded 10. Twin blasts in the southern port city of Basra, meanwhile, killed five people, including a bomb disposal expert looking to defuse one of the rigged vehicles. Three others were killed in bombings in Nasiriyah and Mahmudiyah.