RIYADH, Saudi Arabia – A drone attack on an oil refinery in the Saudi capital caused a small fire but no disruption to supplies, officials said Friday, as crude prices soar after Russia's invasion of Ukraine.

The act of "sabotage and terrorism" follows a series of similar attacks on Saudi facilities by Yemen's Iran-backed Huthi rebels, who are fighting a Saudi-led coalition.

The attack took place in the early hours of Thursday morning.

"The Riyadh oil refinery was attacked by a drone, resulting in a small fire that has been brought under control," the energy ministry said, according to the official Saudi Press Agency, without directly blaming the Huthis.

"The attack did not result in any injury or death, nor was the supply of oil or its derivatives affected."

Brent oil prices have seesawed between $139 and $105 in extreme volatility this week, after the war in Ukraine prompted concerns over supplies.

Saudi Arabia, one of the world's biggest oil exporters, and its partners in the OPEC alliance have come under pressure to raise production to help rein in prices.