"According to our initial estimation, they were brutally murdered by Hamas terrorists a short time before we reached them," said military spokesperson Rear Admiral Daniel Hagari, reported Reuters.

In a post on X, Israel Defence Forces said, “They were all taken hostage on October 7 and were murdered by the Hamas terrorist organization while in captivity in Gaza.”

The bodies of Carmel Gat, Eden Yerushalmi, Hersh Goldberg-Polin, Alexander Lobanov, Almog Sarusi, and Master Sergeant Ori Danino were found and recovered yesterday.

"The heart of an entire nation is shattered to pieces," said President Isaac Herzog, according to Reuters. "I embrace their families with all my heart, and apologize for failing to bring them home safely."

Prime Minister Benjamin Netanyahu did not release a statement immediately over the brutal killing of the hostages.

According to the report, he is under pressure to reach a ceasefire agreement with Hamas that includes the release of remaining hostages.

U.S. President Joe Biden said in a statement he was “devastated and outraged.”

Biden, who monitored the situation of the hostages seized on Oct. 7, said the six included Israeli American Goldberg-Polin.

Senior Hamas official Izzat El-Reshiq said that Israel, in its refusal to sign a ceasefire deal, was responsible for the deaths.

According to Israel's Hagari, hostage Qaid Farhan Alkadi from the Bedouin community in southern Israel, was rescued days earlier, about a kilometre away.

The six recovered bodies were among the 250 hostages taken during Hamas' attack on southern Israel on October 7, which triggered the ongoing war in Gaza.

The assault resulted in around 1,200 deaths, according to Israeli reports.

Since then, the health ministry in Gaza has reported at least 40,691 Palestinians killed and 94,060 injured in Israel's military counter-attack.

Sunday's developments are likely to intensify protests by Israelis demanding a deal for the hostages' release.

The Hostage Families Forum has called on Netanyahu to take responsibility and clarify what is delaying an agreement.