The prospects for ceasefire-hostage negotiations between Israel and Hamas have become more uncertain after the Islamic group added a new demand.

The Washington Post on Saturday quoted relevant officials as saying the US and other mediators are reviewing their proposals for a deal. It said Hamas introduced a new demand for the release of Palestinian prisoners in exchange for hostages.

A key sticking point in the negotiations has been whether the Israeli military should remain at strategic points in the Gaza Strip if a ceasefire is established.

Rallies were held around Israel on Saturday to demand an early agreement with Hamas to pave the way for the release of Israeli hostages.

A rally in Israel's largest business city of Tel Aviv drew tens of thousands of protesters.

Israeli forces have continued their attacks in the Gaza Strip. Palestinian media reports say Israeli airstrikes in northern Gaza on Sunday killed four people.

Palestinian health authorities say that as of Sunday, 40,939 Palestinians had been killed in Gaza since the fighting between Israel and Hamas broke out last October.