Tensions between Yemen’s Houthi rebels and the Saudi-led coalition have escalated following a series of reported attacks on oil facilities, raising concerns over the security of critical energy infrastructure in Saudi Arabia and Yemen.

A fire broke out after the Houthis attacked an administrative building belonging to Saudi state oil company Aramco in Dhahran, in eastern Saudi Arabia. The fire was brought under control, and no casualties were reported, according to Saudi Arabia’s energy ministry.

Earlier, the Saudi-led coalition had ordered the evacuation of the Al-Sabah oil facility in Sanaa, Yemen’s capital, which is controlled by the Houthis. Houthi-linked media later reported that the site had been struck in an air raid.

A spokesperson for the Saudi-led coalition alleged that the Houthis were using the Al-Sabah facility and underground fuel depots to store missiles and drones and support military operations. Yemen’s oil company, however, claimed that its storage facilities had been emptied before the strikes.

Reports also said the Saudi-led coalition had targeted the Ras Isa port and another oil facility in Yemen’s Hodeidah province, an area under Houthi control.

In response, the Houthis declared Saudi oil facilities “legitimate targets.” Houthi spokesperson Yahya Saree warned that any attack on Sanaa would prompt a severe retaliatory response in the Saudi capital, Riyadh.

Meanwhile, Saudi Arabia said it had intercepted missiles launched towards Riyadh. According to the country’s Civil Defence, falling missile debris injured four people and damaged 15 homes.

Amid fears of further attacks, residents and workers were reportedly ordered to evacuate areas around Aramco’s headquarters in Dhahran, King Khalid International Airport in Riyadh, and an oil refinery in the Saudi capital.