The World Health Organization (WHO) has described Gaza's largest hospital as "nearly a cemetery," reports BBC.
Al-Shifa hospital - which is located in the north of Gaza - has been at the front line of intense fighting over the last few days with the Israel Defense Forces (IDF) insisting that Hamas is operating a command-and-control centre in tunnels underneath the hospital.
However, Hamas and the hospital deny this.
WHO spokesman Christian Lindmeier said about 600 people remained in the hospital, with others sheltering in hallways.
A UN spokesperson says, dozens of premature babies and 45 kidney patients needing dialysis can't be treated properly due to a lack of power.
Doctors have also spoken of bodies piling up and rotting at the hospital.
Fighting has been raging close to the hospital in Gaza City in recent days, with severe fuel shortages affecting treatment.
Israel has accused Hamas of having a command and control centre under the hospital - which the facility and Hamas deny.
Israel began striking Gaza after the Hamas attacks on 7 October, in which 1,200 people were killed and more than 200 taken hostage.
The Hamas-run health ministry says more than 11,000 people have been killed in Gaza since - of whom more than 4,500 were children.
Bd-pratidin English/Golam Rosul