Saudi Arabia's oil production has been severely disrupted by drone attacks on two major oil facilities run by state‑owned company Aramco.
Sources said the strikes had reduced production by five million barrels a day ‑ nearly half the kingdom's output.
The fires are now under control at both facilities.
Saudi-led coalition airstrikes regularly target Houthis in Yemen[Photo:BBC]
A spokesman for the Houthi rebel group in Yemen said it had deployed 10 drones in the attacks.
The Saudis lead a Western‑backed military coalition supporting Yemen's government, while Iran backs the Houthi rebels.
The Houthi spokesman, Yahya Sarea says further attacks could be expected in the future.
He said this attack was one of the biggest operations the Houthi forces had undertaken inside Saudi Arabia and was carried out in "co‑operation with the honourable people inside the kingdom".
TV footage showed a huge blaze at Abqaiq, site of Aramco's largest oil processing plant, while a second drone attack started fires in the Khurais oilfield.