The United Nations said Monday that nine employees of its agency for Palestinian refugees (UNRWA) "may have been involved" in the October 7 attack on southern Israel by Hamas, which sparked war in Gaza, and have been fired.

"We have sufficient information in order to take the actions that we're taking -- which is to say, the termination of these nine individuals," UN spokesman Farhan Haq said.

Haq said the organization will need to evaluate any further steps to "fully corroborate" the allegations.

US President Joe Biden held crisis talks on Monday on a potential Iranian counterattack on Israel as his administration said it was working around the clock to avoid all-out war in the Middle East.

Biden and Secretary of State Antony Blinken engaged in frantic diplomacy to try to ease tensions sparked by a suspected Israeli attack that killed Hamas political leader Ismail Haniyeh in Tehran.

Gaza's Civil Defence agency said it received the bodies of 80 unidentified Palestinians from Israel on Monday, which it buried in a mass grave.

"We received 80 bodies inside 15 bags, with more than four martyrs in each bag, each wrapped in a single shroud", Civil Defence director Yamen Abu Suleiman told AFP.

Abu Suleiman said Israeli authorities did not provide any information about the bodies, including their names or where they were found or taken from.

"We do not know if they are martyrs (killed in Gaza) or prisoners from (Israel's) jails", he added.

Security is tight for Israel's team at the Paris Olympics as Mideast tensions spiral amid lingering memories of the 1972 massacre of Israeli athletes at the Munich Games.

The 88 members of the Israeli delegation are accompanied by elite French police and gendarmerie units wherever they go -- a security deployment that is not always easy to manage.

Diplomatic pressure mounted Monday to avert an escalation between Iran and Israel following high-profile killings that have sent regional tensions soaring.

Israeli Prime Minister Benjamin Netanyahu said late Sunday that his country was "determined to stand against" Iran and its allied armed groups "on all fronts".

As its war against Iran-backed Hamas in Gaza nears the 11th month, Israel has been bracing for retaliation from the Tehran-aligned "Axis of Resistance" for the killing of two senior figures.

Once a day, Umm Omar picks up the phone and calls her late husband, humouring their four-year-old daughter who does not understand yet her father was killed early in the Gaza war.

Little Ella "wants us to call him, to tell him about her day", said Umm Omar, who has fled with her three children to Al-Mawasi, a coastal area teeming with mostly displaced Palestinians in the southern Gaza Strip.

More than 40,000 people have been killed in Gaza since war between Israel and Palestinian militants broke out on October 7, the Hamas-run territory's health ministry said Thursday.

Travellers waited in long lines at Beirut airport on Sunday, some after cutting summer holidays short, as airlines have cancelled flights and fears have grown of all-out war between Israel and Hezbollah.

"I'm not happy to leave. I wanted to spend the whole summer in Lebanon then go back to work" in France, said Joelle Sfeir from the crowded departures hall at Beirut airport.

But "my flight was cancelled and I was forced to book another ticket today," she told AFP.

"I cut my trip short so I could find a flight," she added.

Gaza's civil defence agency said an Israeli strike hit two schools in Gaza City on Sunday, killing at least 30 people, while the military reported it had struck Hamas command centres.

These bring to at least 11 the number of schools in Gaza to be struck since July 6, killing around 150 people, based on a tally of tolls previously given by officials in the Hamas-run territory.

"The number of martyrs in the massacre of the Hassan Salameh and Al-Nasr schools' bombing has risen to 30. Dozens were also wounded," civil defence spokesman Mahmud Bassal told AFP.

Algerian teenager Kaylia Nemour conjured up "the performance of her life" to become the first African to win an Olympic gymnastics medal with gold on the uneven bars on Sunday.

The 17-year-old French-born athlete took the title ahead of China's Qiu Qiyuan, who took the world title ahead of the Algerian last year, with American Sunisa Lee snatching bronze.

Defending champion Nina Derwael of Belgium finished fourth.

"I'm so shocked, it's the dream of all my life. I can't believe it has happened, I'm the Olympic champion. I'm speechless," said Nemour.

When Israeli air strikes hit his neighbourhood early on in the Gaza war, Palestinian social worker Tareq Abu Eita, 42, saw his whole life upended in seconds.

The bombardment on October 14 blew in the walls of his two-storey family home.

It killed his 77-year-old father Hamed, his wife of 15 years Muntaha, 37, and his 11-year-old son Ilyas.

It also took the lives of his two nieces, eight-year-old Mira and 14-year-old Tala.