The United Nations health organization released its report early Sunday, just a day after a short and "very high-risk" mission into the hospital on Saturday.
The regime has turned Gaza's hospitals into a specific target of its ongoing war of genocide against the coastal sliver, alleging that those facilities house Palestinian resistance fighters and their equipment.
On Saturday, Mai Alkaila, the Palestinian health minister in the occupied West Bank, strongly condemned Israel for committing genocide against the healthcare system in the Gaza Strip.
Al-Shifa, Gaza's biggest hospital, has taken the brunt of the Israeli assaults on the territory's healthcare system, with the regime claiming that it houses a "command center" belonging to the Palestinian resistance movement Hamas.
The situation has forced "scores of sick and injured, some of them amputees" to flee the hospital towards the seafront without ambulances, along with displaced people, doctors and nurses, the WHO said. It added that only 291 patients, including 32 babies "in extremely critical condition," and 25 health workers have remained inside the complex.
"Signs of shelling and gunfire were evident. The [WHO] team saw a mass grave at the entrance of the hospital and were told more than 80 people were buried there," the world body said in its statement.
A lack of clean water, fuel, medicines, food, and other essential aid has caused the hospital to basically stop functioning as a medical facility, it noted.
"Corridors and the hospital grounds were filled with medical and solid waste, increasing the risk of infection," the WHO said.
Also on Sunday, WHO's chief Tedros Adhanom Ghebreyesus wrote on X social media platform that the world body was "working with partners to develop an urgent evacuation plan and ask for full facilitation of this plan."
"We continue to call for protection of health and of civilians," he said, lamenting that "the current situation is unbearable and unjustifiable. Ceasefire. NOW."
The regime launched its devastating war on October 7 following a surprise operation by Gaza-based resistance movements. At least 12,300 Palestinians have been killed, including more than 5,000 children, and over 29,800 people sustained injuries during the war.