A senior Hamas official has shared with the BBC a list of 34 hostages that the Palestinian group says it is willing to release in the first stage of a potential ceasefire agreement with Israel.
It is unclear how many hostages remain alive.
Among those named are 10 women and 11 older male hostages aged between 50 and 85, as well as young children that Hamas previously said had been killed in an Israeli air strike.
A number of hostages that Hamas says are sick are also included on the list.
Reports from Hamas-run Gaza say Israeli air strikes killed more than 100 people there at the weekend.
The Israeli prime minister's office denied reports that Hamas had provided Israel with a list of hostages.
Ceasefire negotiations resumed in Doha, Qatar, over the weekend, but the talks do not appear to have made significant progress yet.
A Hamas official told Reuters news agency any agreement to return Israeli hostages would depend on a deal for Israel to withdraw from Gaza and a permanent ceasefire or end to the war.
"However, until now, the occupation continues to be obstinate over an agreement over the issues of the ceasefire and withdrawal, and has made no step forward," the official said, speaking on condition of anonymity.
Israel's military campaign to destroy Hamas had killed at least 45,805 people in Gaza as of Saturday, according to the territory's Hamas-run health ministry.
The same source says Israeli air strikes killed 88 people in Gaza on Saturday itself while on Sunday, Reuters news agency quoted health sources as saying a further 17 had died in four separate Israeli attacks on the territory.
The Israeli military said on Sunday that its air force had attacked more than 100 "terrorist" sites across the Gaza Strip over the weekend, killing dozens of Hamas militants.
Source: BBC
Bd-pratidin English/Fariha Nowshin Chinika
