The Islamic Revolutionary Guard Corps announced what it said was the "most devastating offensive operation in the history of the Islamic Republic of Iran”, as Tehran pledged to retaliate for the killing of supreme leader Ayatollah Ali Khamenei.
The IRGC said it had launched "extensive missile and drone" attacks on Israel and 27 US bases in the region, Iranian state media reported. It earlier confirmed Mr Khamenei's death and hailed him as a "martyr”.
Mr Khamenei was killed on Saturday morning during a wave of joint US-Israeli strikes. His daughter, son-in-law and grandson were also killed, said state media.
The Iranian government declared 40 days of mourning after Mr Khamenei's death. The country's Supreme National Security Council Secretary Ali Larijani said Tehran would strike the US and Israel "with a force that they have never experienced before".
At least nine people were killed in an Iranian strike on central Israel, medics said on Sunday. An Iranian ballistic missile attacked Beit Shemesh, with footage showing extensive damage to a bomb shelter. More than 20 others were injured in the attack, the largest since the outbreak of this war.
Israeli Prime Minister Benjamin Netanyahu said Israel was preparing for more forceful attacks on Iran in the coming days.
“Our forces are now striking in the heart of Tehran with increasing intensity, and this will only intensify further in the coming days,” he said in a video address from Tel Aviv. Israel is engaged in "joint efforts with Washington" to deal a "final blow" to Iran's regime, he added.
Israeli army spokesman Nadav Shoshani said Israel killed 40 senior Iranian commanders, including Mr Khamenei, "in one minute", in the opening stage of the joint military campaign launched with the US on Saturday.
Iranian state media confirmed the death of Khamenei's adviser, Ali Shamkhani, and of IRGC commander Mohammad Pakpour in the joint US-Israeli attacks.
Mr Khamenei's killing throws into question the future of the leadership of the Islamic Republic. As supreme leader, he stood above the elected president and had the final say over Iran’s armed forces, including the IRGC.
The council of the Iranian president, the head of the judiciary and one of the jurists of the Guardian Council - Alireza Arafi - will temporarily assume duties of leadership in Iran.
'Wider escalation'
Iran continued to attack what it says are US and Israeli targets in the region on Sunday, drawing condemnation from its neighbours.
The UAE's Defence Ministry said at least three people have been killed and 58 injured by drones and missiles launched from Iran since Saturday. It announced that, since the start of the Iranian attacks on Saturday, 165 ballistic missiles have been launched from Iran towards the country, 152 of which were destroyed. It added that 541 Iranian drones were detected and 506 were intercepted and destroyed, while 35 fell inside UAE territory, causing damage.
Iran's aggression against Gulf nations has "isolated Tehran at a critical moment", said Dr Anwar Gargash, diplomatic adviser to President Sheikh Mohamed.
"Your war is not with your neighbours," wrote the senior UAE official on X. "Return to your senses, to your surroundings, and deal with your neighbours with reason and responsibility before the circle of isolation and escalation widens," he urged Iran.
Kuwait's Health Ministry said at least one person was killed and 32 were injured in Kuwait after missiles and drones were fired from Iran. The country's Ministry of Defence said 97 Iranian ballistic missiles and 283 drones were launched towards the country and were "dealt with in accordance with the rules of engagement".
Qatar’s Interior Ministry said a total of 16 people were injured in the attacks that began on Saturday, with one in critical condition.
US President Donald Trump has warned Iran against striking back after Tehran pledged it would retaliate strongly. "They better not do that, however, because if they do, we will hit them with a force that has never been seen before," Mr Trump wrote on Truth Social.
Meanwhile, Israel announced another wave of attacks on Iran in recent hours, with the army saying it has struck more than 30 targets in the west and centre of the country.
“Dozens of air force fighter jets struck, guided by military intelligence, and completed just a short while ago another wave of strikes to target the ballistic missile array and air defence systems of the Iranian terror regime in western and central Iran,” the Israeli army said.
Reactions to Khamenei's death
Global leaders have called for a quick resolution to the crisis in the Middle East as US allies backed the decision to kill Mr Khamenei. The EU's foreign policy chief Kaja Kallas described the death of Iran's supreme leader as "a defining moment in Iran’s history".
"What comes next is uncertain. But there is now an open path to a different Iran, one that its people may have greater freedom to shape," Ms Kallas said on X.
Iran's allies, Russia and China, have condemned his death as a "grave violation". China's Foreign Ministry said the "killing of Iran’s supreme leader is a grave violation of Iran’s sovereignty and security".
Russian President Vladimir Putin described his death as "a cynical violation of all norms of human morality and international law".
