Iraqi police say the head of Saddam Hussein's tribe has been killed by a bomb planted on his car. Sheik Ali al-Nida is head of Iraq's al-Bu Nasir tribe, a large Sunni Arab clan which includes Saddam's family. An Iraqi police officer says al-Nida and one of his guards died in the explosion Tuesday morning. Three other guards were seriously wounded. The officer spoke on condition of anonymity because he was not authorized to talk to media. He says the bomb exploded while al-Nida drove through the Wadi Shishain area of Tikrit, Saddam's hometown, about 130 kilometers north of Baghdad.