The Israeli military said Wednesday that one of the bodies handed over by Hamas a day earlier under a ceasefire deal was not that of a hostage held in Gaza, adding new strain to the fragile truce in the two-year war.

Hamas turned over four bodies on Tuesday following four others on Monday, hours after the last 20 living hostages were released. Israel has been waiting for the return of 28 deceased hostages in total.

The military said examinations showed the fourth body “does not match any of the hostages.” Officials gave no details about the person’s identity.

Prime Minister Benjamin Netanyahu urged Hamas to fully meet the conditions of the U.S.-brokered ceasefire, which requires the return of all hostages, living and dead. “We will not compromise on this and will not stop our efforts until we return the last deceased hostage,” he said.

Earlier this year, Hamas mistakenly returned the wrong body during a previous truce, prompting renewed scrutiny of its identification process. The group and the Red Cross say recovering remains has been complicated by Gaza’s widespread destruction.

Hamas spokesman Hazem Kassem said on Telegram that the group was “working to return the bodies as agreed,” while accusing Israel of violating the truce with shootings in Gaza City and Rafah.

Meanwhile, forensic teams in Gaza began identifying 45 Palestinian bodies Israel handed over through the Red Cross on Tuesday. It was unclear whether they were prisoners who died in custody or people killed in Gaza.

Humanitarian aid deliveries also resumed Wednesday after a two-day pause linked to the prisoner and hostage exchanges. The Egyptian Red Crescent said 400 trucks carrying food, fuel, and medicine were bound for Gaza.