The fires began after the sites were "targeted by drones," the Saudi Interior Ministry said in a statement carried by the state-run Saudi Press Agency.
Aramco did not immediately respond to questions from AP.
The company describes its Abqaiq oil processing facility in Buqyaq as "the largest crude oil stabilization plant in the world."
Abqaiq, about 60 km (37 miles) southwest of Dhahran in Saudi Arabia’s Eastern Province, contains the world’s largest oil processing plant. Most Saudi oil exported from the Persian Gulf is processed there.
Online videos apparently from Abqaiq, which is near Dammam in the kingdom's Eastern Province, included the sound of gunfire in the background. Smoke rose over the skyline and glowing flames could be seen a distance away.
