Hamas has indefinitely postponed the release of Israeli hostages who were set to be freed from the Gaza Strip this weekend, a spokesman said on Monday, accusing Israel’s government of violating an already fragile cease-fire agreement.

In a statement on Telegram, Abu Obeida, the spokesman for Hamas’s military wing, accused Israel of a host of violations of the cease-fire agreement.

The move threatens to derail the cease-fire agreement reached last month. Widespread anger over the conditions some of the hostages who have been released so far — malnourished, buffeted by hostile crowds, paraded before cameras and in some cases made to read statements under duress — has drawn accusations in Israel that Hamas was not complying with the cease-fire agreement.

A spokesman for Israel’s defense minister, Israel Katz, called Hamas’s announcement “a complete violation of the cease-fire agreement and the hostage release deal.”

He said he had directed Israel’s military “to prepare on highest alert for every possible scenario in Gaza.” Referring to the 2023 Hamas-led attack on Israel that began the war, he added, “We will not allow for the reality of Oct. 7 to return.”

The initial, six-week phase of the cease-fire deal, which is scheduled to last until March 2, called for the release of 25 living hostages and the bodies of 8 who were killed, in exchange for the release of 1,500 Palestinians from Israeli prisons. About half of the exchanges have been made.

This is a developing story. Please check back for updates.

Johnatan Reiss contributed reporting from Tel Aviv.