Yemen's Iran-aligned Houthis said on Tuesday that they struck Saudi Arabia's Ras Tanura oil refinery, the largest in the kingdom, with a ballistic missile. Saudi authorities did not confirm any of the strikes the group described.

The Houthis also said they had attacked Saudi military aircraft and repelled an advance by Saudi-backed forces near the Bab al-Mandab Strait, a key Red Sea shipping route. The growing hostilities between the Houthis and Saudi Arabia have further disrupted oil supplies and raised the risk of a wider regional conflict, eight months after the Iran war began.

Houthi military spokesperson Yahya Saree said the attack on Ras Tanura started a fire at the complex. The site also includes a shipping terminal and sits on the Gulf, west of the Strait of Hormuz. Saree further claimed the group hit the Saudi Ministry of Defense with a ballistic missile and Abha International Airport with a drone.

Bloomberg News cited a person familiar with the matter as saying Saudi Arabia had contained a fire near the Ras Tanura terminal. The refinery has a capacity of 550,000 barrels per day and was shut for a period in the early months of the Iran war as a precaution. Nearly all of Saudi Arabia's oil exports pass through two main ports, Ras Tanura on the Gulf and Yanbu on the Red Sea, and the Houthis have attacked both in the past.

The group also said it targeted two military transport jets at Najran Airport and an airbase in Khamis Mushait. There was no immediate Saudi confirmation of those attacks either.

On Tuesday afternoon, civil defense authorities briefly issued an air raid alert in the capital, Riyadh. The Saudi-led coalition, which fights the Houthis in support of Yemen's internationally recognized government, said it intercepted and destroyed two ballistic missiles that the Houthis launched toward Riyadh.

On the ground, the Houthis said they repelled forces they described as Saudi-backed from the southern approaches to the Bab al-Mandab Strait. Earlier this month, Saudi-backed Yemeni government forces pushed the Houthis out of coastal areas the group had seized in September, loosening its grip on a vital Red Sea oil route. Houthi-affiliated Al Masirah TV also reported Saudi strikes on the Yemeni city of Mocha, which Saudi Arabia has not confirmed.

The fighting has shattered a 2022 UN-brokered truce between the coalition and the Houthis, who control the Yemeni capital, Sanaa.

Diplomatic efforts continue in parallel. On Monday, Saudi Arabia, Turkey and Pakistan met Iranian officials in Tehran in an attempt to reduce regional tensions. Also on Monday, Egypt's parliament, which has said it is considering joining the three countries in a mutual defence pact, authorised the Egyptian military to help defend Saudi Arabia if asked.