The Islamic group Hamas has aired video showing three Israeli hostages it is holding in Gaza, adding that some hostages may have been killed in Israeli attacks.

The video was released on Sunday, the 100th day since the Gaza conflict began following Hamas' assaults on Israeli communities on October 7.

The undated video showed three hostages, who are said to be a 26-year-old woman and two men, aged 38 and 53.

The spokesperson for the Al-Qassam Brigades, the military wing of Hamas, said on Sunday that the fate of Israeli hostages became unknown during the past several weeks due to the aggression of Israeli forces.

The spokesperson also claimed that many of the hostages may have been killed recently, adding that remaining hostages are also exposed to imminent danger.

He ruled out the possibility of starting negotiations for a hostage release, saying "any talks before stopping the Israeli aggression are worthless."

Palestinian media say the Israel military unleashed airstrikes and shelling across Gaza on Sunday, causing many casualties.

Health officials in Gaza said on Sunday Israeli attacks have left 125 people dead over the past 24 hours, raising the death toll in the enclave over the last 100 days to 23,968.

Meanwhile, the Israeli military announced that as of Sunday it has killed about 9,000 Hamas militants and attacked about 30,000 locations, including Hamas-linked facilities.

Israeli Prime Minister Benjamin Netanyahu said on the same day fighting against Hamas will continue for "many more months." He also said his government is "not giving up" on any hostages and is "doing everything" to bring every one of them home.