GENEVA, Switzerland - The head of the World Health Organization on Sunday denounced "the effective destruction" of the Kamal Adwan hospital in the north of Gaza, adding that at least eight patients had died.

Among the deceased patients was a 9-year-old child, said Tedros Adhanom Ghebreyesus in a post on X, formerly Twitter.

His statement came as the Israeli army pulled out of the hospital after an operation lasting several days, claiming it had been used as a command and control centre by Hamas.

Hamas has repeatedly denied such claims.

"@WHO is appalled by the effective destruction of Kamal Adwan hospital in northern #Gaza over the last several days, rendering it non-functional and resulting in the death of at least 8 patients," wrote Tedros.

"Many health workers were reportedly detained, and WHO and partners are urgently seeking information on their status," he added.

Israel's representative to the United Nations posted to X accusing Tedros of making no mention of "Hamas entrenchment in hospitals".

Israel said that before entering the hospital, it had negotiated safe passage for the evacuation of most of the hospital.

The statement by Tedros said: "We learned that many patients had to self-evacuate at great risk to their health and safety, with ambulances unable to reach the facility.

"Of the deceased patients, several died due to lack of adequate health care, including a 9-year-old child.

"We are extremely concerned for the well-being of the internally displaced people who are reportedly sheltering in the hospital building."

All health care facilities in the Gaza Strip have been hit hard by the bombardments and ground invasion launched by Israel following Hamas's unprecedented attack October 7, which according to Israeli figures resulted in 1,140 deaths, mostly civilians, and the capture of around 240 hostages.

Israel's retaliatory strikes on the crowded enclave have killed 18,800 people, of which three-fourths are children, according to the Hamas-run health services.