Residents survey the shattered glass and mangled homes of another blast in the Iraqi capital.<br/> <br />It was the second series of blasts in local suburbs Tuesday that police initially attributed to mortar shells and residents argued were detonated car bombs.<br/> <br />Police and hospital sources later said four car bombs went off simultaneously in Shula, claiming four lives and injuring 11 more.<br/> <br />Angry residents blame the authorities for the surge of violence.<br/> <br />(SOUNDBITE) (Arabic) UNKNOWN RESIDENT OF AREA SAYING:<br/> <br />"Where shall we go? To whom shall we appeal? Where are the checkpoints? What are the police and army doing? They want to cover up their failure so they said that the blasts were caused by mortar shells. We reject such claims and we do not accept such behaviour."<br/> <br />A separate attack in the northwest suburb of Chikok killed seven and injured 16.<br/> <br />Such violence has become a common occurrence as militants hit state targets and Shi'ite neighbourhoods to undermine the government.
