Crude oil futures prices jumped 4 percent Friday after a thwarted attack on a massive oil facility in Saudi Arabia rattled a market already jittery about supply disruptions in Nigeria and Iran's nuclear ambitions. Saudi Arabia is the world's largest oil producer, with output of about 9.5 million barrels per day, or 11 percent of global consumption. The target of the attack, the Abqaiq oil complex in eastern Saudi Arabia, processes about two-thirds of the country's oil before it is exported. Suicide bombers in explosives-packed cars attacked the heavily guarded facility but were foiled when guards opened fire, detonating the vehicles and killing the attackers, Interior Ministry spokesman Lt. Gen. Mansour al-Turki told The Associated Press. The vehicles exploded outside the first of three fences around the sprawling complex, al-Turki said. Saudi oil minister Ali Naimi said the attack caused "a small fire" that was brought under control and that operations were not affected.