More than 50 freed Israeli hostages urged Prime Minister Benjamin Netanyahu to fully implement the Gaza ceasefire deal and secure the release of those still held in the Palestinian territory.

"We who have experienced the inferno know that a return to war is life-threatening for those still left behind," a group of 56 freed hostages said in a letter posted on the social media platform Instagram on Friday evening.

"Implement the agreement in full, in one single manoeuvre."

Among those to sign the letter was Yarden Bibas, whose wife and two young sons died while held captive in Gaza.

Their plea came as Hamas released a video showing Israeli hostage Matan Angrest alive, footage that his family said had left them "shaken".

In the footage, Angrest, who turned 22 in November, also calls on the Israeli authorities to implement the second phase of the Gaza ceasefire deal.

The first phase of the Gaza ceasefire ended on March 1 after six weeks of relative calm that included exchanges of Israeli hostages for Palestinian prisoners, though hostilities have not resumed. 

While Israel has said it wants to extend the first phase until mid-April, Hamas has insisted on a transition to the second phase, which should lead to a permanent end to the war.

Of the 251 hostages taken by Palestinian militants during the 2023 attack on Israel, 58 remain in Gaza, including 34 the Israeli military has said are dead.

On Saturday, a high-level Hamas delegation is expected to hold talks with Egyptian officials over the second phase of the ceasefire, two senior Hamas officials told AFP the day before.

"The delegation will meet with Egyptian officials on Saturday to discuss the latest developments, assess progress in implementing the ceasefire agreement and address matters related to launching the second phase of the deal," one official told AFP.

During its talks with Egyptian mediators, the Hamas delegation will demand that Israel "implement the agreement, begin negotiations for the second phase and open the border crossings to allow humanitarian aid into the Gaza Strip," he said.

The Palestinian militant group wants a "comprehensive agreement that ensures a permanent and complete ceasefire," the other official said.

He said Hamas's demands for the second phase include a full Israeli withdrawal from Gaza, an end to the blockade, the reconstruction of the territory and financial support based on the decisions of this week's Arab summit in Cairo.

He also said that Hamas was ready to "negotiate a prisoner exchange to release all Israeli prisoners including those with American citizenship".