Divya Delhi: The body that Israel received from Hamas was not that of hostage Shiri Bibas, whose remains were supposed to be turned over earlier in the day together with those of her two children and another Israeli man, according to forensic investigation. The Israeli military said in a statement that the body was not that of any known hostage after identification by the nation's National Institute of Forensic Medicine. "This is an anonymous and unidentified body," it read. The military said that by not returning the remains of four hostages, Hamas had violated the ceasefire agreement. Bibas's two boys were recognized by their remains. Kfir Bibas was ten months old and Ariel was four years old when he was killed. According to the military, "based on the information we have and the forensic results of the identification process, terrorists brutally murdered Ariel and Kfir while they were in captivity." Together with their mother, the children were abducted from their Kibbutz home. Nir Under the ceasefire accord, their father, Yarden Bibas, was released after being detained separately. In addition, the body of another hostage, retired journalist and peace campaigner Oded Lifshitz, was already recognized. Ifshitz, an 83-year-old peace campaigner and retired journalist, "was killed while being held captive by the Palestinian Islamic Jihad," according to a statement released by the office of Prime Minister Benjamin Netanyahu. Lifshitz was "murdered" in custody in Gaza "more than a year ago," according to Chen Kugel, head of Israel's National Center of Forensic Medicine, though he did not specify the manner of death. He was murdered in an Israeli attack, according to Islamic Jihad. In the first such transfer since a truce went into effect  the four bodies were turned over to the Red Cross. Israel's state-owned Kan reported, quoting a security official, that Israeli forces passed the coffins via X-ray scanners after receiving them because they were worried that Hamas had booby-trapped them. In Gaza, soldiers fired ceremonial bullets into the air during a brief mourning service. Later, the bodies were taken to the National Center of Forensic Medicine while draped in Israeli flags. Israel was overcome with grief at hearing of the recovery. As the coffins left Gaza, people lined the route, tying yellow ribbons and waving Israeli flags, which are emblems of the effort to return the hostages home. As police cars transported the dead, mourners sung Israel's national song outside the forensic center in southern Tel Aviv. While pictures of the surviving hostages were shown on a big screen, thousands gathered to mourn in Hostage Square, next to the military's headquarters in central Tel Aviv, clutching flags. "Our family's healing process will begin now and will not end until the last hostage is returned," the Lifshitz family stated in a statement.