RAFAH, Palestinian Territories (AFP) — Israel on Tuesday mourned four captives reported dead in Gaza by the army raising doubts to a plan for a ceasefire and hostage release deal outlined by United States President Joe Biden.

Israel’s military on Monday announced the deaths in Gaza of four hostages seized during the 7 October Hamas attack on Israel, naming them as Chaim Perry, Yoram Metzger, Amiram Cooper and Nadav Popplewell.

Their bodies were still in the hands of Hamas, it added.

Cooper, 84, Metzger, 80, and Perry, 80, were abducted from the Nir Oz kibbutz while Israeli-British citizen Popplewell, 51, was kidnapped from the Nirim kibbutz.

British foreign minister David Cameron said he was “greatly saddened to hear about the death” of Popplewell, adding: “we reiterate our demand for Hamas to send all hostages home.”

“They should have returned alive to their country and their families,” the Hostages Families Forum said.

Israel Prime Minister Benjamin Netanyahu, a hawkish veteran leading a fragile hard-right coalition government, is under intense domestic pressure from multiple sides.

Relatives and supporters of hostages have staged mass protests demanding a truce deal -- but his far-right coalition allies are threatening to bring down the government if he agrees to that.

Biden on Friday presented what he labelled an Israeli three-phase plan that would end the bloody conflict, free all hostages and lead to the reconstruction of the devastated Palestinian territory without Hamas in power.

However, Netanyahu’s office stressed that the war would continue until all of Israel’s “goals are achieved,” including the destruction of Hamas’s military and governing capabilities.

Meanwhile, Israeli strikes in Gaza continued early Tuesday, particularly in Bureij where local hospital sources reported several deaths.