Israel has recovered the bodies of six hostages from a tunnel in southern Gaza where they were killed not long before Israeli troops reached them, the military says.
"According to our initial estimation, they were brutally murdered by Hamas terrorists a short time before we reached them," military spokesman Rear Admiral Daniel Hagari told reporters on Sunday.
The bodies of Carmel Gat, Hersh Goldberg-Polin, Eden Yerushalmi, Alexander Lobanov, Almog Sarusi and Ori Danino had been found underground in the city of Rafah and returned to Israel, he said.
"The heart of an entire nation is shattered to pieces," said President Isaac Herzog.
"I embrace their families with all my heart, and apologise for failing to bring them home safely."
There was no immediate comment from Prime Minister Benjamin Netanyahu, who is under pressure at home and abroad to reach a ceasefire deal that includes the release of remaining hostages.
Hamas official Izzat al-Rishq on Sunday blamed Israel for the death of hostages, saying Israel was unwilling to reach a deal.
US President Joe Biden, who has closely followed the fate of the hostages seized on October 7, said the six included Israeli American Goldberg-Polin.
"I am devastated and outraged," Biden said in a statement issued by the White House.
Days earlier, hostage Qaid Farhan Alkadi, a member of the Bedouin community in southern Israel, was rescued about a kilometre away, Israel's Hagari said.
After Alkadi was located, troops were told to be cautious because other hostages might be in the area, but there had been no precise information on their location, he said.
The six recovered bodies were from about 250 hostages taken in Hamas' killing spree through southern Israel on October 7 that sparked the war in Gaza.
About 1200 people were killed in the assault, according to Israeli tallies.
Since then, at least 40,691 Palestinians have been killed and 94,060 injured in Israel's military offensive in Gaza, the enclave's health ministry said in a statement on Saturday.
Sunday's news was likely to spur further protests by Israelis demanding a hostage release deal.
The Hostage Families Forum called on Netanyahu to take responsibility and explain what was holding up an agreement.
"They were all murdered in the last few days, after surviving almost 11 months of abuse, torture, and starvation in Hamas captivity," it said.
"The delay in signing the deal has led to their deaths and those of many other hostages."
Goldberg-Polin, captured at a music festival near Gaza, appeared in a video released by Hamas in late April.
"He had just turned 23; he planned to travel the world," Biden said.
His parents, Rachel Goldberg and Jon Polin, "have been courageous, wise, and steadfast even as they have endured the unimaginable", Biden said.
"They have been relentless and irrepressible champions of their son and of all the hostages held in unconscionable conditions."
Vice President Kamala Harris said in a statement she strongly condemned "Hamas’ continued brutality - and so must the entire world".
Harris, the Democratic candidate running to succeed Biden, said she and he would never waver in their commitment to free the Americans and all those held hostage in Gaza.
