Yemen’s Houthis said on Wednesday they will continue attacks on airports and oil facilities in Saudi Arabia, a day after a strike on the headquarters of state oil company Saudi Aramco in Dhahran.

The group said it fired ballistic missiles, cruise missiles and drones at Aramco facilities in Dhahran, Riyadh airport and an Aramco refinery in Riyadh. It described the attacks as retaliation for Saudi strikes on Yemen and urged shipping companies, civilians and workers to leave Saudi airports and oil facilities.

Saudi Arabia’s energy ministry said Tuesday night’s strike caused a limited fire. Three people with knowledge of the matter told Reuters the fire spread across several floors. Two sources said Aramco operations were continuing, with staff working from home.

The Saudi-led coalition said it intercepted a ballistic missile fired towards Riyadh on Wednesday. Riyadh’s international airport, hit on Saturday in an attack that killed 13 people, is closed until 17 October, and airlines have cancelled flights to Saudi Arabia.

Saudi Arabia hosts a large number of Sri Lankan migrant workers, and the cancelled flights may affect travel plans.