Yemen's Houthi rebels launched drone attacks on the world's largest oil processing facility in Saudi Arabia and a major oil field on Saturday, sparking huge fires and halting about half of the supplies from the world's largest exporter of oil.
The attacks were the latest of many drone assaults on the kingdom's oil infrastructure in recent weeks, but easily the most damaging.
They raise concerns about the global oil supply and likely will further increase tensions across the Persian Gulf amid an escalating crisis between the U.S and Iran over its unraveling nuclear deal with world powers.
The attacks resulted in "the temporary suspension of production operations" at the Abqaiq oil processing facility and the Khurais oil field, Energy Minister Prince Abdulaziz bin Salman said in a statement carried by the state-run 'Saudi Press Agency'.
The fires "were controlled," the statement said, and no workers were injured.
The fires led to the interruption of an estimated 5.7 million barrels in crude supplies, according to the statement, which said part of that would be offset with stockpiles.