The war, now in its seventh day, has dragged in global powers, upended the world's energy and transport sectors, and brought chaos to even usually peaceful areas of the volatile region.

It has spread to Lebanon whose prime minister warned of an impending humanitarian disaster as tens of thousands fled heavy strikes on Beirut's southern suburbs.

Internet coverage in Iran running at about one percent, according to monitor group Netblocks, limiting information about the impact of the war on ordinary Iranians.

In Tehran, worshippers gathered for the first Friday prayers since the start of the war that killed Iran's supreme leader Ayatollah Ali Khamenei on the first day.

Online footage shared by Iranian media showed crowds of men and women dressed in black, some carrying Iranian flags, streaming to an open space outside the Grand Mosque of Imam Khomeini in the capital.

In the background of one video, a man speaking through a loudspeaker mourned the late supreme leader.

"We bear witness that he was the embodiment of piety and guardianship in our time," he said as some worshippers seated on prayer rugs wept.

Friday morning's strikes on Tehran followed warnings from Israel and the US they were escalating attacks.

"We are now moving to the next phase of the operation," Israel's military chief Lieutenant General Eyal Zamir said in a televised statement.

"We have additional surprises ahead which I do not intend to disclose," he added.

US Defense Secretary Pete Hegseth also announced "firepower over Iran and over Tehran is about to surge dramatically".

President Donald Trump said it would be a "waste of time" to send ground troops into Iran, but has insisted he would "have to be involved" in choosing Iran's next leader.

According to Iran's health ministry, US and Israeli strikes on the country have killed 926 people, a number AFP could not independently verify.

Iran has launched missile and drone attacks at Israel and the Gulf since the war began. In Israel, at least 10 people have been killed, according to first responders there.

The US military has reported the deaths of six of its personnel since the war began Saturday.

- 'We were humiliated' -

The conflict has sucked in Israel's neighbour Lebanon after militant group Hezbollah launched missiles in support of its backer Iran.

Israel struck several towns in the south of the country overnight, with widespread destruction in the southern Beirut suburbs, considered a Hezbollah stronghold and home to hundreds of thousands of people.

AFPTV cameras captured a fresh strike on the area on Friday, footage showing plumes of smoke billowing from a building.

The streets were completely deserted on Friday morning, the only movement being a bulldozer working to remove debris.

AFP correspondents on the ground saw scenes of panic and terror on Thursday as residents fled en masse after an unprecedented Israeli order to evacuate immediately if they wanted to save their lives.

Hundreds of families milled around on a Beirut beach, left with nowhere to go.

"We fled from the suburbs, we were humiliated," one man told AFP, declining to give his name.

"We'll sleep on the road tonight and God alone knows what will happen to us."

Lebanon's Prime Minister Nawaf Salam warned that a "humanitarian disaster in looming" from the displacement, saying the consequences could be "unprecedented."

The United Nations refugee agency also said Friday it had declared the crisis a major humanitarian emergency, stressing the need for an immediate response.

The UN's rights chief also called for "impartial investigations" after Iran said a strike on a school that it blamed on the US and Israel killed more than 150 people.

Neither the US nor Israel has said it was behind the strike, although US Secretary of State Marco Rubio said Monday that the Pentagon was investigating.

AFP has neither been able to access the site nor obtain independent confirmation of the toll.

Israel's military chief Zamir has ordered troops to expand the area under his army's control in southern Lebanon, whose health ministry said 123 had been killed in strikes.

Iran has kept up its attacks on Israel, with a volley of missiles aimed at Tel Aviv while rocket trails also lit up the sky in Netanya, further north.

AFP journalists in Tel Aviv reported hearing several blasts over the city after the military said it detected launches from Iran.

- Stranded -

The war has not spared the rich countries of the Gulf, formerly seen as a tourist hot spot and rare Middle East safe haven.

Qatar intercepted a drone attack on a US air base on its territory early Friday, while Saudi Arabia shot down three drones east of its capital Riyadh.

Thirteen people, seven of them civilians, have been killed in Gulf countries since the war began, including Elena Abdullah Hussein, an 11-year-old girl in Kuwait.

The conflict has expanded as far afield as the Sri Lankan coast, where a US submarine torpedoed an Iranian frigate, and Azerbaijan, which threatened retaliation after a drone hit an airport.

Nations have scrambled to repatriate holidaymakers caught up in the fighting with air traffic severely limited as missiles and drones dominate the skies above the region.

The war has also hammered global markets and sent crude oil prices soaring by about a fifth in the week since fighting erupted, all but drying up shipping in the critical Strait of Hormuz.

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