JERUSALEM (AP) — Four more hostages kidnapped on Oct. 7 were declared dead by the Israeli military — including three older men seen in a Hamas video begging to be released. Monday's announcement heightens pressure on the Israeli government to agree to a U.S. cease-fire proposal that could secure the return of the hostages still held in Gaza and end the eight-month war.

About 80 hostages in Gaza are believed to be alive, alongside the remains of 43 others. In the days since President Joe Biden announced the cease-fire proposal Friday, Israel has seen some of its largest protests calling on the government to bring them home. Although Biden said the proposal was Israeli, the Israeli leadership has appeared to distance itself from the plan, vowing to keep conducting military operations against Hamas until the militant group is destroyed.

All four of the men declared dead Monday night — Nadav Popplewell, Amiram Cooper, Yoram Metzger and Haim Peri — were kidnapped and taken into Gaza still alive, according to the Hostages Forum, a grassroots group representing the families of the hostages.

“It is time to end this cycle of sacrifice and neglect,” the group said following the announcement. “Their murder in captivity is a mark of disgrace and a sad reflection on the significance of delaying previous deals.” The group called on the government to immediately approve the new cease-fire plan.

Hundreds of people, including relatives of the captives, gathered outside Israel's Defense Ministry and military headquarters in central Tel Aviv late Monday, calling for a deal. Smaller protests took place across the country.

About 100 captives were released during a weeklong exchange of hostages for Palestinian prisoners in November. Three of the men declared dead Monday had female relatives who were released during the exchange.

Israel’s military spokesman, Rear Adm. Daniel Hagari, said the four hostages were killed while they were together, during the army’s operation in Khan Younis in southern Gaza. He said the four were killed months ago, but that recent operations allowed the military to gather enough intelligence to confirm the deaths.

Their bodies are still being held by Hamas, and the cause of death was not immediately known. Hamas claimed in May that the other hostage pronounced deceased, Nadav Popplewell, died after being wounded in an Israeli airstrike, but provided no evidence. Popplewell was over 50.

“We are checking all of the options. There are a lot of questions," Hagari said.

Cooper, Metzger and Peri were all age 80 or older. They appeared in a video in December released by Hamas under the title, “Don’t let us grow old here.” In the video, the three men appear gaunt, wearing thin white T-shirts.

“We are the generation who built the foundation for the state of Israel,” Peri said, noting that all the men had chronic illnesses. “We do not understand why we have been abandoned here.”

Cooper was an economist and one of the founders of Kibbutz Nir Oz, according to the hostages forum. Metzger helped to found the kibbutz winery and Peri built the community's art gallery and sculpture garden.

Nir Oz was among the hardest-hit towns near the border with Gaza during the Hamas attack Oct. 7, when Palestinian militants stormed Israel, killing some 1,200 people and hauling around 250 hostages back to Gaza.

The news late Monday came after an announcement earlier in the day that the body of a presumed hostage, Dolev Yehud, 35, was found in a community near the Gaza border that Hamas militants had attacked on Oct. 7. Yehud was thought to be among scores of hostages held in Gaza until Monday, when the military announced the discovery of his body and said he had been killed in the initial attack.

Israeli bombardments and ground operations in Gaza have killed more than 36,000 Palestinians, according to Gaza’s Health Ministry, which does not distinguish between combatants and civilians.

Israel has been expanding its offensive in the southern city of Rafah, once the main hub of humanitarian aid operations. The Israeli invasion of Rafah has largely cut off the flow of food, medicine and other supplies to Palestinians facing widespread hunger.