Israel has called securing the freedom of the hostages abducted to Gaza a key goal in its war against Hamas, so many in the country were shocked on Tuesday when it emerged that at least a fifth of the captives were already dead.
The news was likely to worsen a furor in Israel, where a debate over the government’s course of action in Gaza regarding the hostages has become divisive.
Israeli intelligence officers have concluded that at least 30 of the remaining 136 hostages captured by Hamas and its allies on Oct. 7 have died since the start of the war, according to a confidential assessment that was reviewed by The New York Times.
The bodies of two other dead Israelis, killed in 2014 during a previous war between Israel and Hamas, have been held in the territory ever since, bringing the total number of slain hostages inside Gaza to at least 32.
The Israeli government late on Tuesday released a statement saying that only 31 had been confirmed dead; the discrepancy between the two numbers could not be immediately reconciled.
“We have informed 31 families that their captured loved ones are no longer among the living and that we have pronounced them dead,” Rear Adm. Daniel Hagari, the military’s chief spokesman, said Tuesday after The Times published a report about the previously undisclosed hostage deaths.
Four officials said that Israeli intelligence officers were also assessing unconfirmed information that indicated that at least 20 other hostages may have also been killed.
Some of the dead were killed inside Israel on Oct. 7. Their deaths were unconfirmed at the time and they were counted among the hostages, but their bodies were taken by Hamas to Gaza, according to two of the officials.
Others were injured during the Hamas-led assault and died of their injuries after being abducted to Gaza, the officials said. Others still, the officials added, were killed by Hamas once inside Gaza.
At least three hostages were killed by the Israeli military during its ground operations. Another was killed during a failed rescue operation. Israeli soldiers found the bodies of some hostages, intact and without external injuries, inside the warren of tunnels Hamas has dug beneath Gaza. The army has yet to clarify the causes of those deaths.
The figure of 32 deaths is higher than any previous number the Israeli authorities have publicly disclosed.
In January, some family members stormed a meeting at Israel’s Parliament to demand that lawmakers take greater action to secure the captives’ release. That protest and similar demonstrations in recent months have helped expose a societal rift between those who support making a deal with Hamas to secure the captives’ release and those who seek the militant group’s total destruction.
More than 240 hostages were captured by Hamas and its allies during the Oct. 7 raid on southern Israel, prompting Israel to retaliate with massive airstrikes and then a ground invasion. Roughly half of the hostages have been freed, almost all during a temporary truce in November, when they were exchanged for 240 Palestinian prisoners and detainees held in Israeli jails.
Since that truce, the Israeli government has said that its military operations in Gaza would pave the way to further hostage releases. Officials have argued that every Israeli military success places Hamas under more pressure to negotiate another exchange, and makes the military better able to rescue the remaining captives by force.
But scores of survivors and families of the hostages have said that the military campaign is endangering their loved ones’ lives. They want the government to make it a priority to reach a new hostage deal instead of pressing ahead with the invasion, lest their relatives be killed in the crossfire. Only one hostage has been freed by an Israeli military rescue operation.
The debate over the hostages has become particularly acute in recent days, as negotiations over another cease-fire deal — mediated by Egypt and Qatar — have gathered momentum.
Egypt and Qatar have negotiated with the leaders of Hamas on a proposal backed by the United States that could temporarily stop the war, free the remaining hostages there in exchange for Palestinians detained in Israeli jails, and allow more food, water, medicine and other supplies into the territory.
On Tuesday, Hamas said it had received the proposal and delivered a response to the mediators, but did not elaborate.
Right-wing members of Israel’s ruling coalition have threatened to leave Prime Minister Benjamin Netanyahu’s government if he agrees to a deal that allows Hamas to remain in power in exchange for the freedom of all the remaining hostages.
But other members of his coalition, including a centrist former general, Gadi Eisenkot, have suggested that freeing the hostages is a more important goal than further military gains, and that the two goals are mutually incompatible.
Asked for comment, the Israeli military said in a statement that it was “deploying all available resources to locate and retrieve as much information as possible regarding the hostages currently held by Hamas.”
A spokeswoman for the main alliance of hostage families, Liat Bell Sommer, said the alliance was seeking an immediate deal.
“We are aware that there are bodies in Hamas captivity. We are also aware that every day the hostages are held in Hamas tunnels is a death sentence to them,” Ms. Sommer said.
Other hostages may have also already died, but the military has yet to declare them dead because it needs to attain absolute proof before telling their families, according to Avi Kalo, who led a military intelligence department that dealt with prisoners of war and missing people.
“When it comes to the decision about whether to declare a prisoner of war, or a missing person, dead, Israeli intelligence needs 100 percent certainty,” said Mr. Kalo.
“Such a terrible message must not be conveyed except in the case of absolute and final knowledge,” he added.
The Israeli military’s assessment did not conclude that any of the dead hostages were killed in Israeli strikes. But some of the hostages freed in November have said that they fear those still in Gaza could be killed in Israeli salvos. At least one freed hostage said the relentless Israeli bombardment at times felt as menacing as the threat posed by her captors.
“Many times I told myself that, in the end, I will die from Israel’s missiles and not from Hamas,” said Sahar Kalderon, speaking in an interview last December, weeks after being released. Her father remains captured inside Gaza.
“What about my father, who has been left behind?” she said in the interview. “I ask of everyone who sees this: Please, stop this war; get all the hostages out.”
Reporting was contributed by Johnatan Reiss, Aaron Boxerman, Gabby Sobelman and Rawan Sheikh Ahmad.