At least 20 people were killed and more than 40 others wounded on Sunday in two car bomb explosions in Muthanna province of Iraq, a security source told Xinhua."The latest report said that 20 civilians were killed and more than 40 others wounded by the massive blasts of two car bombs in central Samawa of the province," the source said on condition of anonymity.The attacks occurred around noon when one booby-trapped car parked near the provincial government compound detonated, while another car bomb ripped through a busy parking lot in al-Sharji district in downtown Samawa, the source said.The massive blasts set fire to several nearby civilian cars and caused damage to nearby buildings, the source added.Iraq has been witnessing a wave of violence since the Islamic State group took control of parts of Iraq's northern and western regions in June 2014.