Hamas fighters were set Sunday to release a third group of Israeli hostages in exchange for Palestinian prisoners, a day after freeing captives including a young woman snatched from a desert rave.

In a sign of the fragility of the exchanges, the latest swap Saturday was delayed for hours after Hamas accused Israel of breaching its side of the deal that led to a four-day ceasefire in the seven-week-old war.

Despite the dispute, Hamas finally released 13 Israelis and four Thai hostages at night, officials said.

Israel said it in turn freed 39 Palestinian prisoners.

The office of Israeli Prime Minister Benjamin Netanyahu said it had since received a list of hostages due to be released by Hamas on Sunday.

The list was being checked by security officials, it said, and families of the hostages had been informed.

Among the hostages freed late Saturday was 21-year-old Maya Regev, who had been kidnapped while attending the Supernova music festival by Hamas in its deadly October 7 assault on Israel, according to a forum of the hostages' families.

She was the first of the music festival hostages to be released since armed Hamas fighters swooped on the event, killing hundreds, taking captives, and sending others fleeing for their lives.

Maya Regev and her 18-year-old brother Itay, who was also abducted from the festival, were shown tied up in the back of a pick-up truck in a video posted on social media after the attack.

"I am so excited and happy that Maya is on her way to us now. Nonetheless, my heart is split because my son Itay is still in Hamas captivity in Gaza," her mother Mirit said in a statement released by the hostage families' forum.

- 'Sigh of relief' -

The family of Emily Hand, a nine-year-old Israeli-Irish freed hostage, said they were "overjoyed" to embrace her again.

"We can't find the words to describe our emotions after 50 challenging and complicated days," the family said in a statement via the forum.

The girl ran into the tight embrace of her father upon her release, video by the Israeli Defence Forces showed.

"An innocent child who was lost has now been found and returned, and we breathe a massive sigh of relief," said Ireland's prime minister, Leo Varadkar.

Thailand's Prime Minister Srettha Thavisin said the four hostages from his country released Saturday were healthy.

"Everyone is glad to be released. Overall mental health is still good," he said in a social media post. 

Israeli prison authorities said the latest group of released Palestinian detainees included 38-year-old Israa Jaabis, sentenced to 11 years in jail for detonating a gas cylinder at a checkpoint in 2015.

The ceasefire and hostage-for-prisoner swap have brought the first significant relief to both sides since October 7, when Hamas fighters broke through Gaza's militarised border with Israel, snatched around 240 people and killed about 1,200 Israelis and foreigners, according to Israeli authorities.

Israel launched an air, artillery and naval bombardment alongside a ground offensive to destroy Hamas, killing nearly 15,000 people, mostly civilians and including thousands of children, according to the Hamas government in Gaza.

- Ceasefire extension? -

Egypt has said that it received positive feedback from both sides about the idea of extending the truce for a day or two and releasing more hostages and prisoners.

"It's only a start, but so far it's gone well," US President Joe Biden told reporters Friday, adding "the chances are real" for extending the truce.

Jordan's Foreign Minister Ayman Safadi called for "a permanent ceasefire and a complete end to this aggression".

But Israeli armed forces chief Lieutenant General Herzi Halevi said Saturday that the war to eliminate Hamas would continue.

"We will return immediately at the end of the ceasefire to attack Gaza," Halevi said.

"We will also do this in order to dismantle Hamas, also to create a great deal of pressure to return as quickly as possible and as many abductees as possible, every last one of them."

The latest hostage handover was delayed when Hamas said Israel was interfering in the selection of prisoners for release and not allowing aid to reach civilians in Gaza.

Hamas later said it relented when Egyptian and Qatari mediators relayed a promise by Israel to uphold the accord.

Israeli officials denied any breach of the ceasefire's terms, describing Hamas' actions as "psychological warfare".

- West Bank celebrations -

Despite the row, Sundays' release would be the third since the four-day truce entered into force Friday.

Hamas has released 26 Israeli hostages in exchange for 78 Palestinian prisoners in the two releases already completed.

The militants have also freed a total of 14 Thais and one Filipino. Iran's foreign ministry said it had joined with key mediator Qatar to help negotiate the release of the Thai nationals.

Israeli hostages who were let go in the initial swap Friday have since reunited with their families in touching scenes.

Nine-year-old boy Otah rounded the corner of a hospital near Tel Aviv carrying a stuffed toy, breaking into a when he caught sight of his father and hurling himself into his arms, video images showed.

The boy, his mother and grandmother were among those released in the first exchange Friday.

In the Israeli-occupied West Bank, fireworks exploded and crowds filled the streets to welcome the first release of Palestinian prisoners on Friday.

"I was just waiting for the day I would be released from prison so I could hug my mother like this," said Rawan Abu Matar, who served eight years for attempting to stab an Israeli soldier.

Hamas is expected to free a total of 50 hostages during the truce in exchange for 150 Palestinian prisoners, under an agreement brokered by Qatar, Egypt and the United States.

- Aid trucks enter Gaza -

The pause in fighting has also allowed more aid to reach Palestinians struggling to survive with shortages of water and other essentials. Israel had placed Gaza under near-total siege. 

A total of 61 trucks delivered food, water and humanitarian aid via a "humanitarian passageway" to northern Gaza on Saturday, the United Nations office for humanitarian affairs said. 

Another 187 trucks of vital supplies had been sent separately to aid organisations operating in the Gaza Strip, it said.

The UN estimates that 1.7 million of Gaza's 2.4 million people have been displaced by the fighting.

Thousands have been returning since the truce to what is left of their homes.

"We are civilians," said Mahmud Masood, standing in front of flattened buildings in Jabalia, northern Gaza. "Why have they destroyed our houses?"

Palestinian health authorities say Israeli troops killed six Palestinians in the occupied West Bank on Saturday.

The included four people killed by Israeli army fire in Jenin during an incursion by a large number of armoured vehicles, the Palestinian Ministry of Health said.

bur-djw/dhw