Palestinian resistance group Hamas has warned that prisoners may be killed if Israel attempts to retrieve them by force and air strikes continue in Gaza.

The group said in a statement on Wednesday that it was "doing everything possible to keep the occupation's prisoners alive, but the indiscriminate Zionist (Israeli) bombing is endangering their lives".

"Every time the occupation attempts to retrieve its captives by force, it ends up bringing them back in coffins," it said.

Israel restarted intense air strikes across densely populated Gaza last week followed by ground operations, shattering the relative calm afforded by a January ceasefire with Hamas.

Since Israel resumed its attacks in Gaza, at least 830 Palestinians have been killed, according to the health ministry in the besieged enclave.

Netanyahu undermining ceasefire deal

Hamas blamed Israeli Prime Minister Benjamin Netanyahu for undermining a ceasefire and prisoner exchange agreement in Gaza.

"Netanyahu had a premeditated decision to return to war to sabotage the agreement,” Hamas said in a statement.

"Netanyahu bears full responsibility for the failure of the agreement, and the international community and mediators must pressure him to halt the aggression and return to negotiations," it added.

On Tuesday, the Israeli daily Maariv said that there was no proposal being discussed at present for a Gaza ceasefire, adding that the Israeli army was preparing for a new phase of its ongoing assault on Gaza.

The newspaper, citing an Israeli source, said the assault aims to increase pressure on Hamas to show flexibility towards US envoy Steve Witkoff’s proposal to release 10 captives in return of a 50-day ceasefire, release of Palestinian prisoners from Israeli jails, and start of negotiations for the second phase of the ceasefire agreement signed in January 19.

The first phase of the Gaza ceasefire and prisoner exchange agreement ended in early March, but Netanyahu refused to enter negotiations for the second phase of the deal. Instead, he wants to extend the first phase of the deal.

Hamas has refused to proceed under these conditions, insisting that Israel abide by the terms of the ceasefire and immediately start negotiations for the second phase, which includes a full Israeli withdrawal from Gaza and a complete halt to the war.