Yemen's Houthi rebel group claims to have launched a missile at an oil distribution facility in Jeddah operated by Saudi Arabia's state-controlled Saudi Aramco.
The attack has been reported by the Houthi-controlled Saba news agency. Aramco could not be reached for a comment.
Houthi armed forces spokesman brigadier-general Yahya Saree said the missile launch came ahead of planned "large-scale operations in Saudi Arabia" and warned "citizens and foreign companies operating in Saudi Arabia to stay away from important vital installations".
Aramco closed an 85,000 b/d refinery in Jeddah in late 2017 because it was too close to residential neighbourhoods and needed to be expanded to be economically viable. The complex was converted into a distribution hub for oil products.
The Houthis control territory in the northwest of Yemen. Jeddah is approximately 1,200km from the Yemeni border.
Aramco's 400,000 b/d Jizan refinery, currently under construction, is the company's closest facility to the border. The southern Jizan province has been targeted by the Houthis before, but the refinery's construction has continued, and operations are due to commence next year.
