US Secretary of State Mike Pompeo has blamed Iran for Saturday's drone attacks on Saudi oil facilities.

Axar.az reports citing foreign media.

He dismissed a claim by Yemen's Iran-backed Houthi rebels that they had attacked the two facilities, run by state-owned company Aramco.

Iran said the accusations were "blind, incomprehensible and meaningless".

Saudi Arabia's energy minister said the strikes had reduced crude oil production by 5.7 million barrels a day - about half the kingdom's output.

Correspondents say they could have a significant impact on world oil prices.

The main Saudi stock exchange plummeted 3% on opening on Sunday, before recovering.

Saturday's drone attacks hit Abqaiq, site of Aramco's largest oil processing plant, and the Khurais oilfield.

The Saudis lead a Western-backed military coalition supporting Yemen's government, in opposition to the Houthi rebel movement.

The attacks also come against a backdrop of continuing tension between the US and Iran, following US President Donald Trump's abandonment of a deal limiting Iran's nuclear activities and reinstatement of sanctions.