Saudi Arabia shut its 1,200-km East-West oil pipeline after a drone attack hit the conduit in the Riyadh and Medina regions.
Houthi forces reportedly seized Perim Island at Bab el-Mandeb, another strategic point facing disruption alongside the Strait of Hormuz.
Riyadh has sought US military help as attacks on energy infrastructure and shipping put further pressure on regional oil supplies.
Saudi Arabia has temporarily shut its East-West oil pipeline after a drone attack struck the vital crude conduit in the Riyadh and Medina regions, adding pressure to oil supplies as Houthi forces tighten their grip over a key Red Sea shipping route.
The 1,200-km (745-mile) pipeline, which has been carrying between 4 million and 5 million barrels of crude a day in recent months, was closed as a precaution following Thursday morning's attack. The shutdown comes as tanker traffic through the Strait of Hormuz has slowed to a trickle during the six-month war between the United States and Iran, while Iran-aligned Houthi forces have expanded their control along Yemen's Red Sea coast. Global oil prices have moved back above $100 a barrel amid the disruption.
Saudi Arabia, the world's largest crude oil exporter, has relied on the East-West pipeline to move oil across the Arabian Peninsula and bypass the shipping logjam in the Strait of Hormuz. According to ship-tracking companies and analysts, the pipeline's recent throughput of 4 million to 5 million barrels per day represents about 4% to 5% of global supply.
The Saudi Energy Ministry said the pipeline was shut as a precaution. The Saudi Foreign Ministry said the attack resulted in some injuries and that damage was still being assessed, without detailing its impact on oil exports.
Saudi Arabia and Iraq said the drone attack had originated in Iraq, where Iranian-backed militias operate. Satellite images showed black smoke rising from an area of the pipeline south of Medina. It was not immediately clear who was responsible for the strikes.
Houthi forces move towards Bab el-Mandeb
The pipeline attack came as Houthi forces made further gains along Yemen's Red Sea coastline. Four Yemeni government sources told Reuters that the Houthis seized the strategic island of Perim on Friday at the mouth of the Red Sea, in the Bab el-Mandeb strait.
The reported seizure of Perim Island on Friday, a day after the pipeline attack, could represent a dangerous escalation as diplomatic efforts to end the war have stalled.
If the Houthis gain control of the Bab el-Mandeb strait, their backer Iran could gain a critical advantage in its war with the United States.
Yemeni government forces have indicated that they would seek to retake areas captured by the Houthis during their rapid advance along the Red Sea coastline. The Houthis, mountain fighters who withstood years of devastating Saudi airstrikes during Yemen's civil war, have expanded their presence in the area this week.
Reuters reported on Thursday that the Houthi advance down Yemen's Red Sea coast had come with direct guidance from Iran's Revolutionary Guards. Two Iranian sources also said Iran had instructed the Houthis the previous week to escalate their attacks on Saudi Arabia and promised additional funding, weapons and senior officers.
Iran describes the Houthis as an ally but publicly denies giving them military direction, saying they are "not a proxy".
Houthi military spokesperson Yahya Saree said maritime navigation remained safe for all shipping except Saudi vessels subject to a previously announced ban.
Riyadh asks Washington for military help
Saudi Arabia has asked Washington for military assistance against the Houthis as the disruption to regional energy and shipping routes puts further pressure on the kingdom.
Saudi Crown Prince Mohammed bin Salman called US President Donald Trump at least twice on Thursday to request US military help in fighting the Houthis, two sources familiar with the matter told Reuters on Friday. The calls confirmed an earlier report by Axios.
Washington told Riyadh that it was not willing to take direct military action for now, but would assist with intelligence sharing and targeting, the two sources said.
The White House did not address a Reuters question about the reported calls. A senior US administration official, speaking on condition of anonymity, said Washington remained in continuous dialogue with Saudi Arabia and the Yemeni government.
Higher fuel prices during the war have already imposed a political cost on Trump and his Republican Party ahead of the November congressional elections.
Iraq dismisses military commander
The Iraqi government condemned the pipeline attack and dismissed a military commander on Saturday in response to the incident.
The commander had led operations in Maysan province, according to a statement by the Iraqi prime minister's office. Maysan, in southeastern Iraq and bordering Iran, has long been regarded as an area where Iran-backed Shi'ite militias operate and maintain influence.
Saudi Arabia has so far opted against retaliation following a request from the Iraqi prime minister, the Saudi Foreign Ministry said. The kingdom added that it reserved the right to "take all measures necessary" to protect its interests.
Iraq also ordered the closure of the Shalamcheh border crossing between Iraq and Iran as a precaution, two security sources told Reuters. The crossing is one of the main routes used to import vegetables and other food supplies from Iran into Iraq.
The two sources said a wide-scale operation was under way to find those responsible for the pipeline attack.
Saudi crude supplies face further pressure
The pipeline shutdown comes as Saudi crude supply has already fallen to its lowest level in more than three decades, according to the International Energy Agency. The IEA said on Friday that attacks on ships transiting the Bab el-Mandeb by Houthi-linked groups had contributed to the decline.
The East-West pipeline had helped Saudi Arabia bypass the Strait of Hormuz by moving crude across the peninsula towards Red Sea export routes. Its temporary closure comes at a time when tanker traffic through Hormuz has been severely disrupted.
The combination of the Strait of Hormuz disruption and attacks on Red Sea shipping has placed pressure on energy flows on both sides of the Arabian Peninsula and pushed global oil prices back above $100 a barrel.
Iran is expected to meet Gulf states in Oman on Monday to discuss the Strait of Hormuz, Iran's Foreign Ministry said on Friday.
In a post on X on Saturday, Ebrahim Azizi, head of the Iranian parliament's national security committee, said: "As long as the American side does not accept all of Iran's conditions, dialogue and negotiation are of no use."
