The Iran conflict faced a major escalation on Thursday after Iran's massive offshore South Pars natural gas field was targeted by Israel a day earlier — the first known strikes on Iranian energy infrastructure, prompting Tehran to escalate attacks on similar facilities belonging to its Gulf neighbors.

South Pars is the Iranian segment of the world's largest natural gas field, which Iran shares with Qatar across the Gulf. Iran's Fars news agency reported that gas tanks and parts of a refinery had been hit, workers had been evacuated to safety, and firefighters were battling to put out a fire.

Hours after the attack on the field, Qatar said a ballistic missile struck its Ras Laffan natural gas complex, sparking a fire that caused "extensive" damage. Ras Laffan accounts for roughly 20 percent of global LNG supply — a critical pillar of the world's energy security — and Qatar ordered Iran's security and military attaches at its embassy to leave the country within 24 hours.

Tehran also targeted the Habshan gas facility and Bab field in the United Arab Emirates. The Abu Dhabi Media Office said gas operations had been suspended.

In Saudi Arabia, Iran also attacked the vast Eastern Province, home to many major oil fields. In Riyadh, many heard explosions or received text message alerts for the first time since Feb 28. The kingdom reserves the right to take military action against Iran and all trust with Tehran has been shattered, Foreign Minister Prince Faisal bin Farhan warned on Thursday, as regional and Islamic foreign ministers met in the Saudi capital.

Oil prices have surged to nearly $110 a barrel following strikes against energy infrastructure in Iran and the Gulf states.

Over three weeks of war, the United States and Israel had previously refrained from targeting Iran's energy production facilities in the Gulf, a move that could further trigger retaliation against other producers in the region.

Israel's attack on South Pars was widely reported by Israeli media to have been carried out with US consent. However, US President Donald Trump later said Washington "knew nothing" of Israel's attack, vowing that "no more attacks will be made by Israel" on the site if Tehran halts attacks on Qatar, seeking to distance the US from the escalating energy conflict.

In a statement issued on Wednesday, the UAE affirmed that targeting Iran's South Pars gas field represents a serious escalation and constitutes a direct threat to global energy security. Qatar also called the Israeli attack a "dangerous and irresponsible" escalation.

Israel's actions in recent days appear to be part of a "political agenda" aimed at precluding "any kind of diplomatic track" to end the war soon, experts said.

"The attack on the oil installations and now the gas fields raises the escalation ladder, and in many ways, I think, traps the US," Ross Harrison, a senior fellow at the Middle East Institute, told Al Jazeera. "It's very, very difficult now for the United States to deal with all of these contingencies, and we don't really know how the war is going to expand from here."

Meanwhile, Iran's new Supreme Leader Mojtaba Khamenei said in a written message on Wednesday that the killers of Iranian National Security Chief Ali Larijani "will have to pay for it".

"Without a doubt, the assassination of such a figure attests to his importance and to the hatred that the enemies of Islam harbor toward him," Khamenei said, in a message published on his official Telegram channel on the day of Larijani's funeral in Tehran.

Israel also said on Wednesday it had killed Iran's Intelligence Minister Esmail Khatib — the second top Iranian leader assassinated in 48 hours — and his death was later confirmed by Iranian President Masoud Pezeshkian in a post on X.

cuihaipei@chinadaily.com.cn