Houthi military spokesperson Yahya Saree said the group used a drone to target the refinery in southwestern Saudi Arabia.
The Saudi Energy Ministry confirmed that a fire broke out at the refinery but said it was later extinguished, with no injuries reported. Authorities were dealing with the incident, but the ministry did not specify its cause.
The Jazan refinery has a processing capacity of around 400,000 barrels of crude oil per day. The Houthis have previously targeted Aramco facilities in Jazan as well as the Saudi oil port of Yanbu on the Red Sea.
The latest attack came shortly after Saudi Arabia, Pakistan and Turkiye signed the Makkah Joint Defence Agreement. Under the pact, an armed attack against any one of the three countries will be regarded as an attack against all.
It remains unclear whether, or to what extent, Pakistan or Turkiye would become involved in any Saudi response to the Houthi attacks.
Turkish Foreign Minister Hakan Fidan said when the agreement was announced that the pact was not directed against Iran or any other country. He said the three allies would determine through consultations what form and level of support would be provided if one of them came under attack.
Houthis target Yemen's Red Sea port
In a separate statement, Saree said the Houthis also carried out missile and drone attacks on the Yemeni Red Sea port of Mocha.
The port is controlled by Yemen’s internationally recognised government and lies near the strategic Bab el-Mandeb Strait, which connects the Red Sea with the Gulf of Aden and the Indian Ocean.
The Houthis declared a naval blockade against Saudi Arabia in the Red Sea last month, accusing Riyadh of imposing a siege on them. Saudi Arabia has denied the allegation.
Three Yemeni government sources told Reuters that air defences were engaging Houthi drones targeting the commercial quay and storage facilities at the port.
Saree claimed the strikes targeted Saudi troops and weapons stockpiles in the area. There was no immediate Saudi comment on the reported attacks in Yemen.
Yemen's military spokesperson claimed that seven people were killed in the attack on the port, while the country's Transportation Ministry said the strike caused severe damage to port infrastructure.
The ministry described the incident as another attack on a vital civilian facility supporting commercial and maritime activity in the Red Sea.
Regional energy routes under pressure
The escalation comes as the wider conflict involving Iran continues to disrupt key energy and shipping routes.
Iran and allied armed groups have carried out attacks on Saudi Arabia and other Gulf states since the US and Israel launched strikes against Iran on February 28.
Meanwhile, negotiations between the United States and Iran over a possible peace agreement have continued, with the future of the Strait of Hormuz remaining a major obstacle.
The Strait is one of the world's most important energy transit routes, and its disruption has already affected global energy markets.
Further Houthi attacks in the Red Sea could create additional pressure on international shipping and energy supplies by threatening the Bab el-Mandeb, another strategic maritime chokepoint.
Yemen's Saudi-backed Presidential Council head Rashad al-Alimi briefed US officials on the latest developments and called on the international community, particularly the United States, to move beyond containing the Houthi threat and address what he described as its sources and instruments.
Pakistan's military, Air Force, Prime Minister's Office and foreign and information ministries did not immediately respond to requests for comment on the attack. The Turkish government also did not immediately comment on its implications for the newly signed defence pact.
