Doctors Without Borders, or MSF, reported that an Israeli bombardment close to the hospital in the Southern Gaza Strip resulted in the announcement of at least 70 deaths.
The Nasser Medical Complex had to treat dozens of people, including children and teenagers, for severe burns, the organization reported late on Sunday, citing hospital workers.
According to the group, the hospital was one kilometer from the site of the strike in Khan Younis.
A total of 122 patients arrived at the hospital in the immediate aftermath.
“The hospital is overflowing,’’ Doctors without Borders said.
By midday Sunday, the hospital had reported that nearly 50 people had died.
A photographer told dpa there were rows of body bags.
The Israeli army did not immediately comment on the reports.
Saying that it will be safer for them down south, Israel has been pressuring Palestinian civilians to evacuate from the hotly disputed north of the region for weeks.
However, Israeli Defense Minister Yoav Gallant declared on Saturday that there would be a southerly expansion of the attacks in the Gaza Strip shortly.
Approximately 20,000 people fled south on Sunday alone, according to UN estimates.
The figure was based on estimations from UN observers on the ground, according to a report released by the UN Office for the Coordination of Humanitarian Affairs (OCHA) on Monday.
A small number of people traveled on foot, but the majority traveled on buses and donkey carts.
Currently, over 1.7 million people—roughly 75 percent of Gaza’s population—are internally displaced.