The drone attacks led to the interruption of an estimated 5.7 million barrels of crude oil.

Saudi Arabia will invite international experts including from the United Nations to participate in investigating an attack on its oil facilities and called on the world to condemn those behind it, its foreign ministry said on Monday.

Preliminary investigations showed that Iranian weapons were used in the attack, which knocked out more than half of Saudi Arabia's oil production and damaged the world's biggest crude processing plant, the ministry statement said.

"The kingdom is capable of defending its land and people and responding forcefully to those attacks," it added.

The ministry said the attack above all targeted global oil supplies and called it an extension of previous hostile acts against oil pumping stations in May.