Sudanese authorities on Wednesday questioned witnesses in the slaying of an American diplomat who was shot by gunmen in a drive-by attack in the capital. Sudanese officials insisted the shooting was not a terrorist attack but the US embassy said it was too soon to determine the motive. John Granville, 33, an official for the US Agency for International Development, was being driven home at about 4 a.m. Tuesday when another vehicle cut off his car and opened fire before fleeing the scene, the Sudanese Interior Ministry said. The diplomat's driver, Abdel-Rahman Abbas, was killed. Granville initially survived the attack with five gunshot wounds to the hand, shoulder and stomach. He died after surgery, said Walter Braunohler, the public affairs officer at the US Embassy in Khartoum.