US and Arab mediators are working round-the-clock to hammer out a ceasefire deal between Israel and Hamas, sources close to the talks said, while in the Gaza Strip medics said Israeli strikes had killed 13 Palestinians on Thursday.

The mediators, at talks in Egypt and Qatar, seek to forge a deal to pause the 14-month-old war in the Hamas-ruled enclave that would include a release of hostages seized from Israel on October 7, 2023, along with Palestinian prisoners held by Israel.

Mediators had managed to narrow some gaps on previous sticking points but differences remained, the sources said.

In Gaza, medics said at least 13 Palestinians were killed overnight in separate Israeli airstrikes, including on two houses in Gaza City and a central camp.

Residents of Jabalia in the northern Gaza Strip, where the army has operated since October, said forces blew up clusters of houses overnight.

"The longer those talks last, the more destruction and death takes place in Gaza. Jabalia, Beit Hanoun, and Beit Lahiya are being wiped out, Rafah too," said Adel, 60, a resident of Jabalia, who is now displaced in Gaza City.

Palestinians accuse Israel of ethnic cleansing in those areas by depopulating residents to create buffer zones. Israel denies this and says its campaign aims to wipe out Hamas, an Islamist militant group, and to prevent it from regrouping.

Israel accuses Hamas of exploiting civilian infrastructure and the population as a human shield for its activities. Hamas denies it and accuses Israel of trying to justify the indiscriminate killing of Palestinian civilians.

Phased or Comprehensive?

Sources close to the mediation efforts said Hamas had pushed for a one-package deal but Israel wanted a phased one. Talks are focused on a first-phase release of hostages, dead or alive, as well as a number of Palestinians jailed by Israel.

On Tuesday, the sides discussed the numbers and categories of those to be released, but things have yet to be finalized, said a source who spoke anonymously because of the sensitivity of the talks.

The source said one issue was Israel's demand to retain the right to act against any possible military threat from Gaza and the stationing of Israeli forces during phases of the deal.

Israeli Defence Minister Israel Katz said on Tuesday Israel will have security control over Gaza with full freedom of action after defeating Hamas in the enclave.

Israel launched its air and ground assault on Gaza after Hamas-led fighters attacked Israeli communities 14 months ago, killing 1,200 people and taking over 250 hostages back to Gaza, according to Israeli tallies.

Israel says about 100 hostages are still being held, but it is unclear how many are alive.

Israel's campaign has killed more than 45,000 Palestinians, displaced most of the 2.3 million population and reduced much of the coastal enclave to ruins.

On Thursday, Human Rights Watch said Israel had killed thousands of Palestinians in Gaza by denying them clean water which it says legally amounts to acts of genocide and extermination.

Israel's foreign ministry accused the rights group of lying, writing on X that Israel had facilitated the continuous flow of water and humanitarian aid into Gaza since the start of the war despite constant attacks by Hamas.