HILLA - A suicide bomber driving a truck loaded with explosives attacked a security checkpoint in the southern Iraqi city of Hilla on Sunday, killing at least 45 people and wounding more than 100, security officials said.More than 30 cars waiting at the checkpoint were set on fire by the blast, and some of the drivers and passengers were trapped inside. Speaking from a hospital in Hilla, Ahmed Muhammed, a college student, said: “I was sitting in the car waiting to be searched by the police when suddenly it became dark. Then my car was going back, and my legs were no longer there.” The attack killed security officers and civilians, including women and children, officials said. The Iraqiya state television channel said two of its employees were among the dead.No one immediately claimed responsibility for the attack. Bombings and other attacks killed more than 8,000 Iraqis last year, according to the United Nations, and violence has continued unabated this year. Many of the attacks have struck in and around Baghdad and in southern Iraq, but the govt is also battling militants in Anbar Province, in the west, who have seized parts of Falluja and Ramadi.In an interview broadcast on Saturday, Prime Minister Nuri Kamal al-Maliki accused Saudi Arabia and Qatar of supporting terrorism in Iraq and Syria. “I accuse them of inciting and encouraging the terrorist movements,” Mr. Maliki said in the interview with France 24 television. “I accuse them of supporting them politically and in the media, of supporting them with money and by buying weapons for them. I accuse them of leading an open war against the Iraqi government.”Saudi Arabia and Qatar have provided support to groups fighting President Bashar al-Assad of Syria, but both deny backing Al Qaeda’s militants. In other violence on Sunday, gunmen in Salahuddin Province, north of Baghdad, attacked a bus carrying employees of an Iraqi oil company, killing three and wounding nine. In the Abu Ghraib district of western Baghdad, gunmen killed four soldiers at a security checkpoint.