One of the four bodies of captured hostages returned from Gaza to Israel is not Shiri Bibas as Hamas has claimed, Israel has said.
The news that Shiri Bibas, 32, and her two sons Ariel and Kfir, who would now be only five and two, were dead provoked a widespread outpouring of grief in Israel.
But the Israeli military on Thursday said while two bodies were that of Ariel and Kfir, another body was not that of their mother Shiri.
Israel has demanded the return of her body along with the other remaining hostages.
"During the identification process, it was determined that the additional body received is not that of Shiri Bibas, and no match was found for any other hostage. This is an anonymous, unidentified body," the IDF said.
"This is a violation of utmost severity by the Hamas terrorist organisation, which is obligated under the agreement to return four deceased hostages. We demand that Hamas return Shiri home along with all our hostages."
Israeli Prime Minister Benjamin Netanyahu said on Friday Israel would make Hamas pay for failing to release the body of hostage Shiri Bibas as agreed.
"We will act with determination to bring Shiri home along with all our hostages - both living and dead -and ensure Hamas pays the full price for this cruel and evil violation of the agreement," he said in a video statement.
Israeli officials say the two children "were brutally murdered by terrorists in captivity in November 2023", citing intelligence and forensic findings.
Hamas claims the boys and their mother were killed in an Israeli airstrike.
Hamas said in a statement on Friday that it was investigating if there is a possibility of an error or that body parts were mixed due to Israeli strikes.
The mother and children were taken captive from Kibbutz Nir Oz on October 7 2023.
Video of the abduction, with a terrified Shiri Bibas seen swaddling her boys in a blanket and being whisked away by armed men, ricocheted around the world.
Yarden Bibas, the father, was abducted and held separately and released on February 1, as part of the first phase of the ceasefire deal between Israel and Hamas that paused the 15-month war in Gaza.
During the first phase, 33 hostages are to be freed in exchange for nearly 2,000 Palestinians imprisoned by Israel. Eight of those 33 were said by Israel to be dead.
Hamas said it will Israeli hostages Eliya Cohen, Omer Shem Tov, Tal Shoham, Omer Wenkert, Hisham al-Sayed and Avera Mengisto on Saturday.
Since his release, Yarden Bibas has pleaded for information about his family, whose fate has been unclear for much of the war.
While Hamas last year released a video of Yarden Bibas in captivity as a sign of life, nothing had been heard from his wife or children.
Along with the Bibas boys, the body of Oded Lifshitz, who was 83 when he was abducted, was also released.
On Thursday, thousands of Israelis lined the roads from southern Israel to the National Forensic Institute in Tel Aviv.
The Bibas family's struggle became a rallying cry for protesters demanding the hostages be freed.
Concern for their well-being emerged during a November 2023 ceasefire, when most women and children were freed, and grew in recent weeks when living women hostages were freed.
