Israeli hostages Iair Horn, Sagui Dekel-Chen and Sasha (Alexander) Troufanov arrived at a release site in Gaza on Saturday after Egyptian and Qatari mediators helped avert a standoff that threatened to sink a fragile ceasefire.

Hamas fighters led the three onto a stage at the site in Gaza's Khan Younis, live footage showed.

The three have been returned in exchange for 369 Palestinian prisoners and detainees, a swap which eases fears that the agreement could collapse before the end of a 42-day ceasefire.

Hamas had earlier threatened not to release more hostages after it accused Israel of violating the terms of the ceasefire by blocking aid from entering Gaza, drawing counter-threats of a resumption of fighting from Israel.

The emaciated appearance of three hostages released last week and accounts of abuse by other hostages released since January 19 when the ceasefire took effect has set off Israeli protests demanding that the government stick to the ceasefire and proceed with the next stage of the deal to bring all the hostages home.

Prospects for the ceasefire surviving have also been clouded by U.S. President Donald Trump's call for Palestinians to be moved permanently out of Gaza, and for the enclave to be turned over to the United States to be redeveloped. That call was strongly rejected by Palestinian groups, Arab states and Western allies.

The truce was intended to open the way for a second phase of negotiations to return remaining hostages and complete the withdrawal of Israeli forces before a final end to the war and the rebuilding of Gaza, which now lies largely in ruins, facing shortages of food, running water and electricity.

The Hamas threat to hold off from releasing more hostages followed its accusation that Israel had blocked tents and temporary shelter materials from entering into Gaza, leaving tens of thousands exposed to the winter cold.

Israel rejected the accusation, saying it had allowed thousands of aid trucks in. Hamas on Saturday said it expects Israel to meet its aid obligations for the ceasefire to stay on track. (Reuters)