Saudi Arabia launches airstrikes in Yemen following Houthi attacks on oil facilities

Saudi Arabia hit back with a series of strikes on Tuesday after the Iran-backed Houthis targeted oil facilities and other sites across the border in their heaviest attack in years.

The rapid exchange of fire follows the unravelling of a four-year truce in July, months into the war between the United States and Iran.

Saudi strikes hit Taiz province, where deadly fighting has raged for days, and Marib province, the Houthis' Almasirah TV station said. There was no immediate comment from Riyadh.

Overnight, Houthi attacks caused "temporary" shutdowns at oil sites and left 73 injured, authorities said. Saudi officials had vowed to respond.

The latest strikes add to a rapidly deteriorating situation in Yemen, where hundreds have died in recent days as the Houthis try to capture land at the mouth of the Red Sea from the forces of the internationally-recognised government.

The Houthis, who control about one-third of Yemen's territory — albeit the most densely populated parts — are vying to seize the narrow Bab al-Mandeb strait, an increasingly important route for oil after Iran blockaded the Strait of Hormuz, slowing Gulf exports to a trickle.

Houthi attacks on oil infrastructure and Saudi tankers have further contributed to a spike in oil prices, which leapt towards $100 a barrel on Tuesday.

Houthis claim revenge

The group accused Riyadh on Monday of an attack on a prison that killed 11 people and left 20 inmates missing, according to the Houthi-controlled Almasirah TV channel.

The Houthis said they fired dozens of ballistic missiles, hitting Abha International Airport, King Khalid air base and facilities belonging to Saudi state oil giant Aramco in Abha and Jizan.

An energy ministry source told the Saudi Press Agency that "several energy sector facilities and installations" in the south were targeted.

"The attacks caused fires at several locations, leading to a temporary halt in some operations" as well as several injuries, the source said.

Jizan, on the Red Sea coast just north of Saudi's Yemen border, has one of the country's biggest oil refineries with a capacity of 400,000 barrels per day.

According to maritime tracking company Kpler, it was out of action for several weeks until at least 20 August following earlier Houthi attacks.

Saudi Arabia's Foreign Minister Prince Faisal bin Farhan said the door to diplomacy was still open, but Riyadh was ready to defend itself.

"The Kingdom will always support peace and diplomatic solutions," he said during a press conference in Moscow.

"However, (Saudi Arabia) will not hesitate to defend itself, protect its interests, and support measures that secure the interests, security, and stability of brotherly Yemen."

'Spiral of escalation'

The Houthis triggered a return to hostilities in Yemen's civil war in July, when they let an Iranian plane land in defiance of Saudi control of Yemeni airspace. Riyadh retaliated by striking the airport.

The Saudi-led coalition, which has been fighting the Houthis on the internationally recognised government's behalf since 2015, said it would "take all necessary measures and actions to respond to the sources of the threat and neutralise its danger".

Andreas Krieg, a Gulf expert from King's College London, said the Houthi attacks create an "extremely uncomfortable dilemma" for Crown Prince Mohammed bin Salman, the de facto Saudi ruler.

After years of trying to withdraw from the Yemen war, "restraint now carries the risk of allowing the Houthis to dictate the spiral of escalation," he said.

"Saudi Arabia's immediate response is likely to remain measured, involving airstrikes, intelligence support, and the reinforcement of Yemeni government forces," Krieg added.

"Should attacks on Saudi cities persist, maintaining this restraint will become increasingly difficult. In effect, the Houthis are testing exactly where Riyadh's true red line now lies."

Formally known as Ansar Allah, the Houthis came to power in late 2014 after storming Sana'a and seizing the presidential palace and key military sites, forcing Yemen's government into exile.

The group is part of Tehran's so-called Axis of Resistance — a loose network of militant groups in several countries in the region including Hezbollah in Lebanon, Hamas in Gaza and militias in Iraq, all backed, trained and equipped by the IRGC to varying degrees.

While the Houthis do not control the part of Yemen’s coastline along Bab el-Mandeb, they hold territory less than 100 kilometres away.

The strait, whose name in Arabic means "Gate of Tears," connects the southern Red Sea to the Gulf of Aden and the Indian Ocean, and carries roughly 12% of global maritime trade.

The Houthis disrupted it severely with their campaign against Israel-linked shipping during the Israel-Hamas war in Gaza, claiming it was a show of support for Palestinians.