Israeli forces shelled the Nasser Hospital in Khan Younis, southern Gaza, on Sunday evening, killing a 13-year-old girl being treated at the facility.
Dina Abu Mohsen had her leg amputated after an Israeli airstrike killed both her parents and two siblings.
She was one of more than 50,000 Palestinians wounded in Israel's brutal offensive on Gaza, which began on 7 October, many with life-changing injuries.
Several women and children were injured in Israeli strikes on the medical complex including the maternity ward, the Palestinian Red Crescent said.
Nasser Hospital is one of several health facilities that has been targeted in Israeli strikes in recent weeks.
Hospitals, as well as mosques and churches, have sheltered many of Gaza's displaced, despite Israeli strikes in these facilities.
Israeli forces stormed the Awda Hospital in the Jabalia refugee camp on Sunday evening, after it was besieged for several days.
Medics and hospital staff were beaten, stripped, and interrogated by Israeli soldiers, a Gaza health ministry spokesperson said.
The Kamal Adwan Hospital in the northern Gaza city of Beit Lahiya was also raided with the WHO saying it was "appalled by the effective destruction" of the facility.
At least patients eight patients were killed in the attack, including a nine-year-old boy who passed away due to lack of medical treatment.
In a video, health officials were seen trying to address journalists gathered outside the hospital on Sunday, with the sound of gunfire ringing in the background.
Gaza health ministry head Munir al-Bursh said dozens of staff had been arrested by Israeli forces.
"During the siege of the hospital, the displaced and medical staff were gathered in a large basin meant for collecting sewage water," al-Bursh told the press.
Staff and displaced people "were stripped naked, humiliated, and wild dogs were released on them".
Israel’s air and ground attacks in the Gaza Strip have killed over 18,800 people, most of them women and children, according to the Palestinian territory’s health ministry.