DUBAI: Saudi Arabia sharpened its warnings to Iran early on Monday, telling Tehran it would be the "biggest loser" if it continues to attack Arab states.
The Saudi statement came after a new drone attack apparently targeted its massive Shaybah oil field.
The kingdom dismissed comments by Iranian President Masoud Pezeshkian on Saturday that Iran had halted its attacks on Gulf Arab states.
"The kingdom affirms that the Iranian side has not implemented this statement in practice, neither during the Iranian president's speech nor afterward," Saudi Arabia's Foreign Ministry said in a statement. "Iran has continued its aggression based on flimsy pretexts devoid of any factual basis."
It added that the Iranian attacks mean "further escalation which will have grave impact on the relations, currently and in the future".
Mojtaba Khamenei, a son of Iran's slain supreme leader, has been named as the Islamic Republic's next ruler, authorities announced on Monday, as Tehran widened its attacks across the Mideast to strike oil and water facilities crucial to its desert sheikdoms.
With Iran's theocracy under assault by the US and Israel for more than a week, the country's Assembly of Experts chose as the next supreme leader a secretive, 56-year-old cleric who maintains close ties to the country's paramilitary Revolutionary Guard. The Guard has been firing missiles and drones at Israel and Gulf Arab states since the younger Khamenei's father, Ayatollah Ali Khamenei, was killed on February 28 during the war's opening salvo.
The war has shaken global energy markets, pushing oil prices above USD 100 a barrel and leading to tighter supplies of natural gas after Qatar turned off its production.
The younger Khamenei, who had not been seen or heard from publicly since the war started, had long been considered a contender for the post. That was even before the Israeli strike killed his father, and despite never being elected or appointed to a government position.
There appeared to be some dissension over his selection. Political figures within Iran criticised the idea of handing over the supreme leader's title based on heredity and thereby creating a clerical version of the rule of the shah, who was toppled during the 1979 Islamic Revolution. But top clerics in the Assembly of Experts likely wanted Khamenei to prosecute the war.
Khamenei, who is believed to hold views that are even more hard-line than his late father, now will be in charge of Iran's armed forces and any decision regarding Tehran's nuclear programme.
While the country's key nuclear sites are in tatters after the United States bombed them during the 12-day Israel-Iran war in June, there is still highly-enriched uranium in Iran that is a technical step away from weapons-grade levels. Khamenei could choose to do what his father never did -- pursue the bomb.
Israel has already described him as a potential target, while US President Donald Trump criticised the idea of Khamenei taking power.
"Khamenei's son is unacceptable to me," Trump has said. "We want someone that will bring harmony and peace to Iran."
The White House did not immediately respond to a request for comment. Trump told ABC News on Sunday he wants a say in who comes to power once the war is over; a new leader "is not going to last long" without his approval.
Iran's Revolutionary Guard issued a statement expressing support, as did the Iran-backed Lebanese militant group Hezbollah.
Top Iranian security official Ali Larijani, speaking to Iranian state television, praised the Assembly of Experts for "courageously" convening even as airstrikes continued in Tehran. He said the younger Khamenei had been trained by his father and "can handle this situation".
Regional anger grows and oil rises above USD 100 a barrel
Oil depots in Tehran smoldered following overnight Israeli strikes.
In a sign of rising regional anger, the Arab League chief lashed out at Iran for its "reckless policy" of attacking neighbours, including ones that host US forces.
Saudi Arabia's Defence Ministry said on Monday it intercepted a drone attacking the country's massive Shaybah oil field. A day earlier, the country said a military projectile fell onto a residential area and killed two people of Indian and Bangladeshi nationality.
The US military said a service member died of injuries from an Iranian attack on troops in Saudi Arabia on March 1. Seven US soldiers have now been killed.
Two US officials said the State Department will order nonessential personnel and families of all staff to leave Saudi Arabia as Iran escalates its attacks. The officials spoke on condition of anonymity pending a formal announcement. Eight other US diplomatic missions have ordered all but key staff to leave: Bahrain, Iraq, Jordan, Kuwait, Lebanon, Qatar, the United Arab Emirates and the consulate in Karachi, Pakistan.
The war has killed at least 1,230 people in Iran, at least 397 in Lebanon and at least 11 in Israel, according to officials. Israel reported its first soldier deaths on Sunday, saying two were killed in southern Lebanon, where its military is fighting Hezbollah.
Desalination and oil facilities attacked
Bahrain accused Iran of indiscriminately attacking civilian targets and damaging one of its desalination plants, though its electricity and water authority said supplies remained online.
Desalination plants supply water to millions of residents in the region and thousands of stranded travellers, raising new fears of catastrophic risks in parched desert nations.