Leading Iranian activists and filmmakers on Monday called for an end to hostilities between Iran and Israel, urging Tehran to stop the conflict by halting its enrichment of uranium.

"We demand the immediate halt of uranium enrichment by the Islamic Republic, the cessation of military hostilities, an end to attacks on vital infrastructure in both Iran and Israel, and the stopping of massacres of civilians in both countries," said the activists in an op-ed in French newspaper Le Monde.

Iran's supreme leader, Ayatollah Ali Khamenei, has weathered a series of challenges but Israel's unprecedented strikes mark his most serious crisis yet, threatening both the clerical system he leads and his own physical survival.

Khamenei, Iran's top leader since the death of Ayatollah Ruhollah Khomeini in 1989, has ruled in the face of sanctions, near constant international tensions as well as protests that were ruthlessly repressed, most recently the 2022-2023 women-led uprising.

Geopolitical tensions roiled the opening of the Paris Air Show on Monday as French authorities sealed off Israeli weapons industry booths amid the conflicts in Iran and Gaza, a move that Israel condemned as "outrageous".

The decision added drama to the major aerospace industry event, which was already under the shadow of last week's deadly crash of Air India's Boeing 787 Dreamliner.

Black walls were installed around the stands of five Israeli defence firms at the trade fair in Le Bourget, an airfield on the outskirts of Paris.

After an Iranian strike early Monday gouged a gaping hole in his apartment building in central Israel, Idan Bar said he feared for his family as the air war between the longtime foe escalated.

A tangle of metal protruded from the charred section of a high-rise building in Petah Tivka near Tel Aviv, as rescuers wheeled elderly residents away from the damage.

One woman's mouth hung open as she was taken away in a wheelchair.

"My building got bombed from Iran," Bar told AFP.

Israel and Iran traded deadly fire for a fourth day on Monday in their most intense confrontation in history, fuelling fears of a drawn-out conflict that could engulf the Middle East.

The longtime foes have fought a prolonged shadow war through proxies and covert operations, with Israel battling several Iran-backed groups in the region, including Hamas in the Gaza Strip since October 2023.

Here are the latest developments:

- Mounting casualties -

France on Monday blocked access to the stands of five Israeli arms manufacturers at the Paris Air show for displaying "offensive weapons", according to a French government source.

A black wall blocked off stands run by Israel Aerospace Industries (IAI), Rafael, Uvision, Elbit and Aeronautics for showing "offensive weapons", including those used in Gaza, which allegedly violated terms made with Israel, said the source.

Rafael, Elbit and IAI produce guided bombs and missiles, while Uvision and Aeronautics produce drones.

Prime Minister Benjamin Netanyahu insisted on Monday that Israel's campaign against Iran was "changing the face of the Middle East", as the two countries traded heavy strikes for a fourth day.

The remarks came hours after a dramatic attack on an Iranian state TV building, which forced a presenter to flee mid-broadcast and prompted a threat of retaliation against Israeli news channels.

A German court on Monday handed a life sentence to a Syrian doctor who tortured opponents of former ruler Bashar al-Assad during the country's brutal civil war.

The higher regional court in Frankfurt found Alaa Mousa, 40, guilty of crimes against humanity, committed while working as a doctor at military hospitals in Homs and Damascus between 2011 and 2012.

Mousa's actions were "part of a brutal reaction by Assad's dictatorial, unjust regime", presiding judge Christoph Koller said as he read out the verdict.

US President Donald Trump vetoed an Israeli plan to assassinate Iranian supreme leader Ayatollah Ali Khamenei, a senior US official told AFP Sunday.

"We found out that the Israelis had plans to hit Iran's supreme leader. President Trump was against it and we told the Israelis not to," said the US official, speaking on condition of anonymity.

Earlier Sunday, Israeli Prime Minister Benjamin Netanyahu dodged a question about reports that Trump had asked his country not to kill Khamenei.

"I'm not going to get into that," he told Fox News.

Israel's unprecedented strikes on Iran, which have killed top military leaders and nuclear scientists, required years of meticulous intelligence gathering and infiltration, experts say.

Israel said it hit hundreds of targets on Friday alone, and has since continued its attacks, striking a defence facility and fuel depots on Sunday.

The fiercest-ever exchange of fire between the arch foes came in the midst of ongoing talks between Tehran and Washington seeking to reach a deal on Iran's nuclear programme.