Israel and Iran exchanged fire again on Thursday, the seventh day of the war between the longtime enemies.

Here are the latest developments:

Hospital strike

A hospital in southern Israel was hit as Iran fired "dozens" of missiles, officials said, with impacts also reported in two Israeli towns close to commercial hub Tel Aviv.

The Soroka Hospital in Beersheba was left in flames, and its director Shlomi Codish said 40 people had sustained injuries.

"Several wards were completely demolished and there is extensive damage across the entire hospital," he said.

Iran said the main target of its missile attack was not the hospital but a nearby military and intelligence base.

The International Committee of the Red Cross said "hospitals must be respected and protected", citing international law.

UN rights chief Volker Turk urged restraint from both Iran and Israel, saying it is "appalling to see how civilians are treated as collateral damage in the conduct of hostilities".

Meanwhile, Israeli Prime Minister Benjamin Netanyahu said Tehran would pay a "heavy price".

Israel threatens Khamenei

Speaking in Beersheba after the hospital strike, Netanyahu said Israel was "committed to destroying... the threat of a nuclear annihilation" as well as Iran's ballistic missile capabilities.

His defence minister, Israel Katz, said Iran's supreme leader Ayatollah Ali Khamenei "can no longer be allowed to exist".

"Khamenei openly declares that he wants Israel destroyed -- he personally gives the order to fire on hospitals," Katz told reporters. "Such a man can no longer be allowed to exist."

President Donald Trump said Tuesday that the United States was aware of Khamenei's location but would not kill him "for now".

Iraq's top Shiite cleric Grand Ayatollah Ali Sistani warned that any targeting of Iran's "supreme religious and political leadership" would have "dire consequences on the region".

Trump mulls joining

Trump said Wednesday he was considering whether to join Israel's strikes, and that Iran had reached out seeking negotiations on ending the conflict.

"I may do it, I may not do it," Trump told reporters. "I can tell you this, that Iran's got a lot of trouble, and they want to negotiate."

Iran and European diplomats said nuclear talks will be held in Geneva on Friday, bringing together top diplomats from Britain, France, Germany and the European Union as well as Tehran's Abbas Araghchi.

The Wall Street Journal reported Trump has told aides he has approved attack plans but is holding off to see if Iran will give up its nuclear program.

A key Iranian government body, the Guardian Council, warned against any US involvement in the war, threatening a "harsh response" if "the criminal American government and its stupid president... take action against Islamic Iran".

Tehran ally Moscow said any US military action "would be an extremely dangerous step", while pro-Iran groups in Iraq threatened retaliatory attacks.

A senior US diplomat, Tom Barrack, warned the Iran-backed Lebanese group Hezbollah against getting involved in the war, which he said in Beirut "would be a very, very, very bad decision".

Nuclear sites, missile launchers

The Israeli military said it struck an "inactive nuclear reactor" in Arak in overnight raids on Iran that also saw the uranium enrichment facility in Natanz targeted again.

It said the strike on the Arak site was carried out "to prevent the reactor from being restored".

Netanyahu told Israeli public broadcaster Kan that Israel had destroyed "more than half" of Iran's missile launchers since Friday.

"I said that we're changing the face of the Middle East, and now I say we're changing the face of the world," he said.

Iran's Revolutionary Guards said more than 100 "combat and suicide" drones were launched at Israel on Thursday.

Arrests

Iranian police announced the arrest on Thursday of 24 people accused of spying for Israel and "trying to disturb public opinion and to tarnish and destroy the image of the sacred system of the Islamic Republic of Iran", according to a statement carried by Tasnim news agency.

Authorities in both Israel and Iran have announced arrests for espionage and other charges since the war began on Friday.

Norway-based NGO Iran Human Rights said at least 223 people have been arrested nationwide on charges related to collaboration with Israel, cautioning that the actual figure was likely higher.