Saudi Arabia issued alerts on Thursday warning of potential danger in Yanbu, the kingdom's Red Sea oil export hub, as Yemen's Iran-aligned Houthis continue attacks on the kingdom that have opened another front in the US-Israeli war on Iran.

The Saudi-led coalition fighting the Houthis in Yemen said it destroyed a missile launched by the group towards Islam's holy city of Medina. The kingdom's civil defence also issued emergency alerts for the southeastern area of Sharurah that borders Yemen.

The Houthis had yet to claim any attack on the kingdom on Thursday. They said on Wednesday they had attacked Riyadh's international airport while Syria's President Ahmed al-Sharaa visited the kingdom. Saudi authorities have not confirmed the attack.

The Syrian leader witnessed theg of a defence agreement alongside Crown Prince Mohammed bin Salman - their second meeting in Saudi Arabia in less than a month. No details were provided on what the agreement entails.

Reuters reported last month that Damascus was carefully weighing providing military assistance to Riyadh. Saudi Arabia, the world's biggest oil exporter and a key US ally, has been requesting assistance from countries ranging from the US to Europe and the Middle East, for both defensive and offensive support in its renewed war against the Yemeni militia.

Egypt last month gave approval for its military, one of the region's biggest, to provide help to the kingdom. Meanwhile, Turkey is set to ratify a mutual defence pact with Saudi Arabia and Pakistan that includes a collective defence clause, committing NATO's second-largest army to Riyadh's defence.

Britain said in October it will fly fighter jets on defensive missions to help protect Saudi cities from Houthi aerial attacks.