At least 33 people were killed and 63 others injured on Sunday in two car bomb explosions in Muthanna province of Iraq, a security source said."Our reports said that 33 civilians were killed and 63 others wounded by the massive blasts of two car bombs in central Samawa," the source told Xinhua 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.Earlier, the source put the toll at 20 killed and more than 40 wounded.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.