Saudi Arabia said drones struck an oil facility in the capital of Riyadh on Friday, igniting a fire at the installation.
The official Saudi Press Agency quoted an official in the energy ministry as saying the dawn attack caused no injuries or damage, and did not affect oil supplies.
“The Riyadh oil refinery was attacked by drones, resulting in a fire that has been brought under control,” the ministry said in a statement.
It called on the world to stand against what the ministry described as “these terrorist and subversive aggressions and those carrying them out or supporting them”.
Earlier on Friday, Yemen’s Iran-aligned Houthi rebels reported they launched six drones at a facility belonging to Saudi Aramco, the kingdom’s oil giant that now has a sliver of its worth traded publicly on the stock market, in Riyadh.
Saudi Arabia condemned the attack saying the assault targeted “the security and stability of the world’s energy supplies”.
Aramco did not immediately respond to a request for comment but said it would do so “at the earliest opportunity”.
Authorities did not name the impacted facility. Aramco, the kingdom’s oil giant, does have a refinery just southeast of Riyadh. That refinery produces gasoline, diesel, jet fuel and other products for consumption around the kingdom’s capital.
The Houthis have stepped up attacks into Saudi Arabia, the world’s top oil exporter, in recent weeks.
“Our armed forces carried out at dawn today an operation … with six drones which targeted the Aramco company in the capital of the Saudi enemy, Riyadh,” said Yahya Sarea, a Houthi military spokesman, without describing the targets he said were hit.
Sarea said operations against Saudi Arabia will continue and escalate as long as Saudi “aggression” against Yemen continues. He also warned “foreign companies and citizens” to avoid military sites and key infrastructure.
The United States on Friday condemned the drone strike on the Saudi oil refinery.
“We condemn the Houthis’ attempts to disrupt global energy supplies by targeting Saudi infrastructure,” State Department deputy spokeswoman Jalina Porter told reporters. “This behaviour shows an utter lack of concern for the safety of the civilian population either working or living near the sites.”
A Saudi-led coalition has been battling the Houthis since March 2015, months after the rebels seized Yemen’s capital, Sanaa. The war has ground into a stalemate since then, with Saudi Arabia facing international criticism for its air strikes killing civilians.
The United Nations has described the situation in Yemen as the world’s worst humanitarian disaster with mass hunger, disease, and poverty largely caused by the war. Now mired in stalemate, the conflict has killed about 130,000 people — including more than 12,000 civilians.
Saudi Arabia says it intercepts most of the drones and missiles that the Houthis launch at airports, air bases and energy infrastructure, but some do inflict damage.
On March 7, the coalition said a barrage of drones and missiles were intercepted en route to targets including an oil storage yard at Ras Tanura, the site of a refinery and the world’s biggest offshore oil-loading facility.
A residential compound in Dhahran used by Saudi Aramco was also targeted.
In renewed diplomatic efforts to end the war, the United Nations and United States have urged the Houthis – who are also pressing an offensive against the government-held city of Marib in Yemen – to turn to negotiations rather then military escalation.