Desperately needed humanitarian aid has begun to flow into war-battered Gaza after Israel and Hamas conducted the first exchange of prisoners agreed under the terms of the ceasefire.

Gazans displaced by more than 15 months of genocidal war have been walking through an apocalyptic landscape to return to whatever remains of their homes, while rescuers trawl the rubble for bodies.

"Gaza is like a massive demolition site," Trump said as he signed a flurry of executive orders following his inauguration.

When asked whether he believed the two sides would maintain the truce, Trump said, "That's not our war; it's their war. But I'm not confident."

Trump had claimed credit for the three-phase ceasefire agreement announced by Qatar, Egypt and the United States ahead of his return to the White House, following months of fruitless negotiations under his predecessor, Joe Biden.

Trump has made clear he would support Israel. In one of his first acts as president, he revoked sanctions on Israeli terrorist settlers in the West Bank imposed by the Biden administration over deadly attacks against Palestinians.

Israeli Prime Minister Benjamin Netanyahu and Palestinian President Mahmud Abbas congratulated Trump on his return.
 

'We will rebuild'
 

Displaced Gazan Ghadeer Abdul Rabbo, 30, told AFP she hopes that "with or without Trump", the ceasefire will hold and world governments will help "maintain this calm because we are afraid".

If all goes to plan, during the initial, 42-day phase of the truce that began Sunday, a total of 33 captives are to be returned from Gaza in exchange for around 1,900 Palestinians.

Over those six weeks, the parties are meant to negotiate a permanent ceasefire.

In Rafah, in southern Gaza, Ismail Madi said "We have endured immense hardships, but we will stay here. We will rebuild this place."

Three Israeli captives, all women, were released on Sunday.

Hours later, 90 Palestinian prisoners were reunited with their families after being freed from an Israeli jail.

The first group of Palestinians released under the deal left Ofer prison in the West Bank early Monday, with jubilant crowds celebrating their arrival in the nearby town of Beitunia.

One freed detainee, Abdul Aziz Muhammad Atawneh, described the prison as "hell, hell, hell".

Another, Khalida Jarrar of the leftist Popular Front for the Liberation of Palestine said prison conditions were harsh and that she had been kept "in solitary confinement for six months".

The next prisoner swap should take place on Saturday, a senior Hamas official told AFP.

There was anxiety in Israel over the next phases of the truce, with columnist Sima Kadmon warning in the Yedioth Ahronoth daily that the coming captive releases may be more painful than the first.

'Beautiful feeling'
 

In southern Gaza, Ammar Barbakh, 35, spent the truce's first night in a tent on the rubble of his home.

"This is the first time I sleep comfortably and I'm not afraid," he said.

"It's a beautiful feeling, and I hope the ceasefire continues."

The war has devastated much of the Gaza Strip and displaced the vast majority of its population of 2.4 million and Israel has killed 47,000 people, a majority of them and wounded over 110,000 others in 15 months of relentless bombardments and ground incursions. 

More than 900 trucks carrying humanitarian aid entered Gaza on Monday, the United Nations said.

The day the deal came into force, 630 trucks entered Gaza.

Qatar, which was key in negotiating the truce, said that 12.5 million litres of fuel would enter Gaza over the first 10 days.

* This story was edited by Ahram Online.