Yemen's Houthi rebels claimed responsibility for firing ten drones targeting two state-run Aramco oil facilities in Saudi Arabia. The world's largest oil processing plant in Abqaiq and the kingdom's second-biggest oil field in Khurais came under attack. As a result, oil production fell by 50%, which is about 5% of the global daily crude supply.
Iranian President Hassan Rouhani called the latest drone attacks "legitimate self-defence" by Yemen after years of Saudi-led coalition bombings of their country.
"What Yemenis have done is legitimate self-defence, and a reciprocal attack," Rouhani said on Monday, speaking to reporters in Ankara following talks between the presidents of Turkey, Russia and Iran.
The Shiite Houthi movement has been fighting a Saudi-led coalition since March 2015, when Saudi Arabia and other Gulf nations began carrying out airstrikes against the Houthis, attempting to restore the rule of President Mansour Hadi, ousted in 2014.
The conflict in Yemen is also seen as part of a regional power struggle between Shia-ruled Iran and Sunni-ruled Saudi Arabia.
Houthis often fire missiles into Saudi Arabia, and in May, they launched drone attacks on Saudi Arabia's oil pipeline, striking the Shaybah oil field in August. Despite Houthis claiming responsibility for those attacks, the United States and Saudi Arabia have blamed Iran for the incidents, and accused Tehran of supplying Yemeni rebels with drones and other weapons.
Muhammed Al Sabban, a Saudi economic expert, has called the attack "the most powerful and destructive" of all previous attacks.
"The peculiarity of this attack is that it disrupted the work at the Khurais oil field. Production plunged by 5.7 million barrels of oil per day; there are also gas losses that account for 49% of normal daily volumes," he said.
The Saudi economic expert pointed the finger at Iran, saying it was behind the attacks:
"Saudi Arabia will definitely respond to this aggression. In the kingdom, many want retaliatory attacks on Tehran's oil infrastructure. These demands by the Saudi public will persist for several more weeks," Al Sabban said.
Saudi General Hasan Al Shahri, in his turn, said that it is pointless to blame someone while an investigation is still ongoing. Who ordered the attack, where the drones were launched from, all this will soon become known. The kingdom will make up for oil production losses using other fields. "Saudi Arabia does not plan to retaliate. This could lead to war. But this is exactly what mercenary groups in Yemen, Lebanon, and Iraq want. For its part, Saudi Arabia seeks peace and stability in the region," the Saudi general explained.