Hamas said on Sunday it was prepared to coordinate with the Red Cross to deliver aid to hostages it holds in Gaza, if Israel meets certain conditions, after a video it released showing an emaciated captive drew sharp criticism from Western powers.

Hamas said any coordination with the Red Cross is contingent upon Israel permanently opening humanitarian corridors and halting airstrikes during the distribution of aid.

According to Israeli officials, 50 hostages now remain in Gaza, only 20 of whom are believed to be alive. Hamas, thus far, has barred humanitarian organisations from having any kind of access to the hostages and families have little or no details of their conditions.

On Saturday, Hamas released its second video in two days of Israeli hostage Evyatar David. In it, David, skeletally thin, is shown digging a hole that, he says in the video, is for his own grave.

The arm of the individual holding the camera, which can be seen in the frame, is a regular width.

The video of David drew criticism from Western powers and horrified Israelis. France, Germany, the UK and the US were among countries to express outrage and Israel's foreign ministry announced that the UN Security Council will hold a special session on Tuesday morning on the issue of the situation of the hostages in Gaza.

Israeli Prime Minister Benjamin Netanyahu said on Sunday he had asked the Red Cross to give humanitarian assistance to the hostages during a conversation with the head of the Swiss-based ICRC's local delegation.

This comes as Gaza's health ministry said six more people died of starvation or malnutrition in the enclave over the past 24 hours.

The new deaths raised the toll of those dying from what international humanitarian agencies say may be an unfolding famine to 175, including 93 children, since the war began, the ministry said.

Israel blames Hamas for the suffering in Gaza but, in response to a rising international uproar, it announced steps last week to let more aid reach the population, including pausing fighting for part of the day in some areas, approving air drops and announcing protected routes for aid convoys.

UN agencies say airdrops are insufficient and that Israel must let in far more aid by land and open up access to the territory to prevent starvation among its 2.2 million people, most of whom are displaced amidst vast swathes of rubble.

Meanwhile, Belgium's air force dropped the first in a series of its aid packages into Gaza on Sunday in a joint operation with Jordan, the Belgian defence ministry said.

France on Friday started to air-drop 40 tons of humanitarian aid.

Palestinian health authorities said at least 80 people had been killed by Israeli gunfire and airstrikes across the coastal enclave on Sunday. Deaths included persons trying to make their way to aid distribution points in southern and central areas of Gaza, Palestinian medics said.

Among those killed was a staff member of the Palestinian Red Crescent Society, which said an Israeli strike at its headquarters in Khan Younis in southern Gaza ignited a fire on the first floor of the building. (Reuters)