BAGHDAD - Car bombs killed 30 people in Iraq on Sunday and wounded more than 70 in one of the bloodiest spasms of violence of recent weeks. At least 21 people were killed and 52 wounded when a suicide bomber detonated a car on a crowded street in the ShiÂ’ite holy city of Kerbala, south of Baghdad, police and doctors said. The effect was devastating.The police chief told a news conference only two people had died in the bombing. But police and hospital officials who declined to be named stood by their casualty figures and said rescue work was continuing four hours later. The blast decimated crowds going about their business at the start of the working week, close to a partially built ShiÂ’ite mosque and some 500 metres from the main bus station. A dozen other vehicles burned out as a result of the explosion.