Men walk among debris in Nuseirat refugee camp in the central Gaza Strip on Sunday. Reuters

At least 274 Palestinians, including dozens of children, were killed, and hundreds more were wounded, in the Israeli raid that rescued four hostages held by Hamas, Gaza's Health Ministry said on Sunday.

The Israeli bombing was "hell,” witness Mohamed al-Habash told reporters.

"We saw many fighter jets flying over the area. We saw people fleeing in the streets. Women and children were screaming and crying.”

Saturday's events also affected fragile attempts to deliver humanitarian aid. The World Food Program (WFP) chief said they suspended distribution around a US-built pier off Gaza because "two of our warehouses, warehouse complex, were rocketed yesterday.”

When asked how it happened and whether WFP shares its locations with Israel's military, Cindy McCain said they did and "I don't know. It's a good question.”

It wasn't clear if she was referring to the rescue operation.

In Gaza, medics described scenes of chaos after the raid. Overwhelmed hospitals were already struggling to treat the wounded from days of heavy Israeli strikes in the area.

"We had the gamut of war wounds, trauma wounds, from amputations to eviscerations to trauma, to TBIs (traumatic brain injuries), fractures and, obviously, big burns,” said Karin Huster of Doctors Without Borders, an international charity working in Al-Aqsa Martyrs Hospital.

"Kids completely gray or white from the shock, burnt, screaming for their parents. Many of them are not screaming because they are in shock.”

International pressure is mounting on Israel to limit civilian bloodshed in its war in Gaza. Palestinians also face widespread hunger because fighting and Israeli restrictions have largely cut off the flow of aid.

Associated Press