Hamas informed negotiators on Monday that not all of the 33 hostages who would be freed in the first phase of a possible cease-fire deal with Israel are still living and that the remains of those who have died would be among the initial releases, according to two people familiar with the talks.

The disclosure came as part of Hamas’s counteroffer to Israel’s latest proposal, which envisions a first-phase, six-week cease-fire in exchange for the return of some of the hostages taken during the Oct. 7 terrorist attacks. It was not clear whether Hamas revealed how many of the 33 are still alive and how many are dead.

The first group of hostages meant to be freed in the initial phase of the proposed agreement is supposed to include women, older men and the sick and wounded who are among the more than 100 believed still to be held captive. The Israelis initially wanted 40 to be released in the first phase but came to understand that Hamas did not hold that many who fit the criteria. Israeli and American officials have long assumed that some of the hostages may be dead.

The news that the first group of hostages to be released would include the remains of some taken seven months ago will surely upset families who have been pressing the Israeli government to do more to free their loved ones. The fate of the hostages has become a major issue with the Israeli public as thousands of demonstrators have poured into the streets to pressure Prime Minister Benjamin Netanyahu’s government to make a deal. Protesters blocked major roads in Jerusalem and Tel Aviv late Monday after Hamas’s counteroffer.

Israeli officials said that the Hamas counteroffer was not acceptable, but they have agreed to keep negotiating. Officials from various countries serving as intermediaries will gather again in Cairo this week to go over the counteroffer and see if further progress can be made. Israel has agreed to send a delegation to review the proposal and contemplate further concessions.