The US has reportedly identified locations in Iran from which drones and cruise missiles were launched against major Saudi oil facilities on Saturday.
Senior officials told Newsmen that the locations were in southern Iran, at the northern end of the Gulf.
Saudi air defences did not stop the drones and missiles because they were pointed southwards, to prevent attacks from Yemen, the officials added.
Iran denies involvement in the attacks, which disrupted global oil supplies.
Oil prices soared 20% after the attacks but have since pared their gains. The international benchmark used by traders, Brent crude, is currently trading at around $65.34 (£52.32).