Doctors and the Palestinian Red Crescent in Gaza said Israel has told them to evacuate a key hospital in Gaza City.
There are 400 patients being treated inside Al-Quds Hospital and moving them is impossible, the organisation said.
Around 14,000 civilians are also understood to be sheltering in the hospital and its grounds.
Overnight, thousands in Gaza broke into aid depots taking flour and other basic supplies, the UN relief agency for Palestinian refugees said.
The Israel Defense Forces (IDF) said more troops entered the territory overnight, while warplanes attacked more than 450 Hamas targets.
Israel has been bombing Gaza since the 7 October Hamas attacks that killed 1,400 people and saw 230 people kidnapped as hostages.
The Hamas-run health ministry in Gaza says more than 8,000 people have been killed since Israel’s retaliatory bombing began.
This brings the total number of deaths to 9, 400.
