• Israel denied they were killed by strikes. Its defence minister accused the militants of "psychological abuse".
• He added that military pressure was essential to release more hostages.
Hamas has issued a new video purporting to show the bodies of two Israeli hostages, with the militants claiming that they died in air strikes on Gaza.
It comes a day after Hamas released another video of the hostages when they were alive, but warning they could die if Israel continued its bombardment.
Israel denied they were killed by strikes. Its defence minister accused the militants of "psychological abuse".
He added that military pressure was essential to release more hostages.
The video released on Monday shows a woman named as Noa Argamani, speaking under duress and saying that two men with whom she had been held had been killed in captivity.
She says the men - one of whom was identified as Itay Svirsky, 38 - were killed by "our own IDF strikes", referring to the Israel Defense Forces.
She added that they were buried under rubble after the strikes, but that Hamas fighters had "succeeded in saving my life". It was not clear when the video was taken.
In response, IDF Spokesperson Daniel Hagari said the hostages had not been killed by Israeli forces. "This is a Hamas lie," he said in a statement. "The building where they were being held was not a target."
Israeli Defence Minister Yoav Gallant said: "Hamas is severely beaten by Israeli forces, what is left for them is to lash out at the sensitive nerves of the Israeli society through the psychological abuse of the (Israeli) family members."
He also insisted that continued military pressure remained vital. "They only talk to us when they want something," Mr Gallant said. "The moment we give them ceasefire without a price, they won't talk to us."
The video released by Hamas on Sunday showed Ms Argamani, 26, along with the two men when they were alive. It urges the Israeli government to stop its offensive and bring about their release.
That footage ends with the caption: "Tomorrow (Monday) we will inform you of their fate."
Ms Argamani, Mr Svirsky and the third hostage mentioned in the videos were among 240 people taken by militants in a series of Hamas raids in southern Israel on 7 October.
About 1,300 people, mainly civilians, were also killed in those attacks. About 132 hostages are still being held in Gaza.
The raids triggered Israel's intense bombardment of Gaza, which have killed more than 24,000 people so far, according to the Hamas-run health ministry.
Palestinian officials say that 85% of Gaza's population has been displaced. While more aid is now getting into Gaza the UN's humanitarian chief has described the situation as "intolerable".
Israeli forces continued to bomb targets across the Gaza Strip on Monday, and clashed with militants in southern and central areas.
Mr Gallant said that the intensive phase of operations against Hamas would soon come to an end in southern Gaza.