Pope Francis on Wednesday met separately with Israeli relatives of Hamas hostages and Palestinians with family in Gaza, while warning the ongoing conflict could result in "a mountain of dead".

At the end of his weekly audience at the Vatican, the 86-year-old pontiff called for prayers for peace, saying of both groups: "They suffer so much and I heard how they both suffer."

One year after the Qatar World Cup, billboards emblazoned with the tournament's official slogan, "All is now," still stand by Doha's roadsides.

As the months have passed, the signs, in Qatar's trademark maroon, have steadily faded in the relentless glare of the desert sun.

Calm has returned to Doha, 12 months after the gas-rich emirate attracted hordes of fans -- and rancorous debate -- for the first World Cup in the Muslim world.

The head of the United Nations children's agency on Wednesday called the besieged Gaza Strip "the most dangerous place in the world to be a child," and said that the hard-won truce deal between Israel and Hamas was not enough to save their lives.

UNICEF's executive director Catherine Russell told the UN Security Council that over 5,300 children have reportedly been killed in Gaza since Hamas' October 7 attack on Israel, accounting for 40 percent of the deaths.

Israeli and Palestinian families were torn between hope and fear Wednesday following an overnight deal to free hostages held by Hamas in Gaza in exchange for Palestinian prisoners held by Israel.

Under the terms of the deal, Palestinian militants will release 50 hostages, all women and children kidnapped during the October 7 Hamas attack on southern Israel, in exchange for the freeing of 150 Palestinian prisoners, made up of women and teenagers.

Following the announcement that Gaza militant group Hamas will release at least 50 hostages as part of a deal with Israel, here is what we know about the captives.

Based on interviews with relatives and Israeli media reports, AFP has confirmed the identities of 210 of the around 240 people abducted on October 7 during Hamas attacks on military posts, communities and a desert music festival.

The hostages, who are set for staggered release in return for a four-day truce and the release of Palestinian prisoners, are women and children and included both Israelis and foreigners.

The Israel-Palestinian peace camp has long promoted dialogue against hatred and bloodshed but the passions inflamed by the deadliest Gaza war yet pose entirely new challenges for the movement.

Many of its activists believe that talking to each other is now more important than ever, at a time when the fighting rages unabated and both sides mourn their dead.

"It wasn't easy before the war," said Sulaiman Khatib of Combatants for Peace, a group he co-founded in 2006 and whose Israeli and Palestinian members hold weekly meetings and frequent protests.

UK foreign minister David Cameron on Wednesday met with Arab and Islamic counterparts to discuss how to secure the release of remaining hostages held by Hamas and to increase aid into Gaza.

Cameron earlier welcomed a truce deal between Israel and Hamas allowing at least 50 hostages and scores of Palestinian prisoners to be freed, while offering besieged Gaza residents a four-day truce.

"This agreement is a crucial step towards providing relief to the families of the hostages and addressing the humanitarian crisis in Gaza," Cameron said in a statement.

A secret cell headed by CIA and Mossad chiefs, and multiple contacts between US President Joe Biden and leaders of Israel, Qatar, and Egypt underpinned an "excruciating" five weeks resulting in the truce agreement, a US official said.

In a detailed account to reporters by a senior US official speaking on condition of anonymity, a picture has emerged of a tense international effort beset by sudden communication cutoffs with Hamas, disputes over hostage lists, and safety concerns on the ground.

For the past decade, Nasser Jabbar and his children have lived in a rundown house built of grey concrete blocks at a shantytown in southern Iraq.

Drought chased the father of 10 out of the countryside, where he had been a herder and farmer, and into a life of unemployment and urban poverty.

"We lost the land and we lost the water," said the father in his 40s, wearing a traditional white robe.

He spoke to AFP in his home on the edges of Nasiriyah, capital of Dhi Qar province.

Israel said a four-day Gaza truce and hostage release will not start until at least Friday, delaying a breakthrough deal to pause the brutal war with Hamas.

National security adviser Tzachi Hanegbi indicated the phased release of at least 50 hostages in return for 150 Palestinian prisoners would still go ahead but not on Thursday as expected.

"The contacts on the release of our hostages are advancing and continuing constantly," he said in a statement about the agreed deal to free mostly women and people aged 18 and under on both sides.