The Israeli military says it has mistakenly killed three hostages during its campaign in Gaza after they were mis-identified as a "threat".
They were named as Yotam Haim, 28, Samer Talalka, 22, and Alon Shamriz, 26.
The military shared its remorse and said the three were shot by troops operating in Shejaiya, in Gaza`s north.
More than 100 hostages remain in captivity in Gaza after being captured in the 7 October attacks on Israel.
The Israel Defense Forces (IDF) said Friday`s incident was under investigation, and that it "expresses deep remorse over the tragic incident and sends the families its heartfelt condolences".
"Our national mission is to locate the missing and return all the hostages home," it added.
Hundreds of people gathered in central Tel Aviv following the announcement and marched to an IDF military base in the city, calling on the government to secure a deal for the release of the remaining hostages.
Demonstrators held candles and carried placards that read "Bring
home" and "Hostage exchange now!"The bodies of the three men have been returned to Israeli territory, where checks confirmed their identities.
Yotam Haim, who was kidnapped from Kibbutz Kfar Aza on 7 October, was a musician who loved animals and cooking Italian food.
On the morning of the Hamas attack, he called his family and told them that his house was on fire. When he opened the window for some fresh air, Yotam was kidnapped by Hamas.
Speaking to the BBC before her son`s death, his mother said they had messaged each other as they hid in their home shelters - before their connection was lost.
Alon Shamriz was at also Kfar Aza at the time of attack. His family gave permission for him to be named after asking earlier that his identity not be revealed.
Samer Talalka, a Bedouin, was kidnapped from Kibbutz Nir Am. An avid motorcycle enthusiast, he loved to travel in the countryside and spend time with friends.
He lived in the town of Hura and worked at a chicken hatchery in the kibbutz. On the morning of 7 October, he was at work. He called his sister after the attack to tell her that he had been injured by gunfire.
His father told local media they lost touch at 07:00 local time on the morning of the attacks. A photograph of him being led through Gaza was shared on Telegram.
IMAGE SOURCE, REUTERS: Hundreds of people marched through central Tel Aviv on Friday calling on the Israeli government to secure the release of the remaining hostages
Israel`s Prime Minister Benjamin Netanyahu called their deaths an "unbearable tragedy".
"Even on this difficult evening, we will bind up our wounds, learn the lessons and continue with a supreme effort to return all our abductees home safely," he said.
White House spokesperson John Kirby said the killings were a "tragic mistake," and that the US did not have "perfect visibility on exactly how this operation unfolded".
More than 100 hostages remain in captivity in Gaza after being captured on 7 October when Hamas attacked Israel, killing 1,200 people and taking 240 hostages - some of whom were released during a brief truce.
The Hamas-run Gaza health ministry says more than 18,800 people have been killed and 50,000 injured in the enclave so far in the war that followed.
Hen Avigdori, whose wife and daughter were among the released, said he often heard people say hostages could be rescued "by military means."
But "there is no military way" that would bring them back safely, he wrote in a post on X, formerly known as Twitter.
"The conclusion for every person who has both heart and mind is the same: Israel must initiate a deal to bring them back alive and not in coffins."