Several neighbourhoods in the capital were hit in successive waves of attacks, with the Israeli military saying it targeted military centres.

Iranian authorities have provided few details about the extent of the damage, and internet connectivity remained largely blocked for a second consecutive day.

Khamenei and several top commanders were killed in Tehran at the outset of the conflict on Saturday.

In response, senior officials moved swiftly to emphasise continuity within the Islamic Republic’s political system.

Under procedures established after Iran’s 1979 Islamic Revolution, the Assembly of Experts is responsible for selecting a new supreme leader.

President Masoud Pezeshkian said a new leadership council “has begun its work”, while Foreign Minister Abbas Araghchi said the process to appoint a successor could be completed within days.

Until then, a three-member council will govern. Alongside Pezeshkian, judiciary chief Gholam-Hossein Mohseni-Ejei and Alireza Arafi were named to the body.

Arafi is a member of the powerful Guardian Council, with the Expediency Council selecting the jurisprudence expert to serve as interim leader.

The powerful Islamic Revolutionary Guard Corps (IRGC) is also expected to play a decisive role.

Its commander-in-chief, Mohammad Pakpour, who had been appointed less than a year ago, was among those killed on Saturday.

Also reported killed were armed forces chief of staff Abdolrahim Mousavi, Defence Council head Ali Shamkhani and police intelligence chief Gholam-Reza Rezaeian.

The IRGC vowed retaliation, announcing what it described as “the heaviest offensive operations” in the country’s history against Israeli territory and US bases in the region.

Army chief Amir Hatami said Iranian forces would continue defending the country, while officials claimed fighter jets had carried out bombing runs against US positions without releasing evidence.

Police chief Ahmad-Reza Radan said security forces were prepared to maintain public order, as Washington and Israel publicly urged Iranians to take to the streets against the government.

Senior adviser Ali Larijani endorsed the constitutional transition process and sought to reassure neighbouring countries facing incoming Iranian missiles and drones.

Writing in Arabic on social media, he said Iran did not seek to target its neighbours but considered US bases there to be “American territory”.

In a separate English-language post, he warned of unprecedented retaliation.

Another senior official, Ali Akbar Ahmadian, said the Supreme Defence Council would continue functioning despite the loss of key members.

Prominent political and religious figures rallied around the system.

Hassan Khomeini, grandson of Islamic Republic founder Ruhollah Khomeini, praised Khamenei as a “hero” and stressed the need to defend the Islamic Republic.

Former presidents Hassan Rouhani and Mohammad Khatami also voiced support for the interim leadership while condemning the assassination.

Conflicting reports emerged over the fate of former president Mahmoud Ahmadinejad.

Some local outlets reported he had been killed in an Israeli strike in eastern Tehran, but the state-linked Iranian Labour News Agency denied the claim, citing an informed source.

Footage circulating online showed damage in Tehran’s Narmak district, including near 72 Square, where Ahmadinejad is reported to reside.

A nearby school was damaged, and at least two children were killed, local authorities said.

Separately, officials reported that more than 150 people, many of them children, died in a strike on a school in Minab in southern Iran.

US and Israeli officials have signalled that air operations could continue for days or weeks, targeting state and military infrastructure.

Inside Iran, the balance of power remains uncertain as the country absorbs the loss of a leader who had ruled unchallenged for 36 years.

The government has declared seven days of public holidays and 40 days of national mourning, with large gatherings organised across the country to commemorate Khamenei.