RIYADH: A drone strike sparked a fire at a Riyadh oil refinery Friday, in an attack claimed by Yemen’s Huthi rebels as the Iran-backed insurgents made major advances on the embattled Yemeni city of Marib.

The attack at dawn on the refinery is the second major assault this month on Saudi energy installations, highlighting a dangerous escalation of Yemen’s six-year conflict between the Saudi-backed Yemeni government and the Iran-linked Huthis.

“The Riyadh oil refinery was attacked by drones, resulting in a fire that has been brought under control,” the Saudi energy ministry said in a statement, adding that no casualties were reported and oil supplies were not disrupted.

Strongly condemning the “cowardly attack”, the ministry said the drone strikes were not just an assault on the kingdom but the world economy and global energy security.

In a statement, the Huthi rebels claimed to have targeted energy giant Aramco in Riyadh on Friday with six drones in response to the “brutal aggression” of the Saudi-backed military coalition in Yemen.