The head of the World Health Organization on Tuesday said he deplored the strikes on the Palestine Red Crescent Society headquarters in Gaza, branding them "unconscionable".
WHO chief Tedros Adhanom Ghebreyesus said health must never be a target during conflicts, adding that Gazans were facing a "dire humanitarian catastrophe".
The Palestine Red Crescent Society (PRCS) said that Israel twice struck its headquarters in the southern city of Khan Yunis, resulting in "five casualties and three injuries" among displaced people who had sought refuge there and at a nearby hospital, AFP reports.
"I deplore today's strikes on the PRCS-run Al-Amal hospital," Tedros said on X, formerly Twitter.
He said WHO staff and colleagues from the UN humanitarian agency OCHA undertook a mission to the facilities on Tuesday, "where they witnessed extensive damage and displacement of civilians".
Tedros claimed that 14,000 people were sheltering at the hospital.
"Many of them have now left, and those remaining are extremely fearful for their safety and planning to leave a place they had turned to for refuge and protection," the UN health agency's chief said.
"Hospitals, ambulances, health workers, and people seeking care must be protected, at all times, under international humanitarian law," he said.
"Today's bombardments are unconscionable. Gaza's health system is already on its knees, with health and aid workers continuously stymied in their efforts to save lives due to the hostilities."
- 'Unspeakable conditions' -
He reiterated his call for an immediate ceasefire, alongside urgent action to get food, medical supplies and water to Gazan civilians "forced to live in unspeakable conditions of hunger, disease spread, and lack of hygiene and sanitation".
Tedros added that only a "fraction" of Gazans needing medical evacuation were being taken out of the Palestinian territory.
"This is unacceptable in light of the dire humanitarian catastrophe which has unfolded over three months," the Ethiopian former health minister said.
Israel has vowed to destroy Hamas in retaliation for the October 7 attack which left about 1,140 people dead, mostly civilians, according to an AFP tally based on Israeli figures.
The Hamas militants, whose movement has ruled the Gaza Strip since 2007, also took around 250 hostages, 129 of whom remain in captivity, according to Israeli figures.
After the worst attack in its history, Israel began a relentless bombardment and ground offensive that has killed at least 22,185 people, mostly women and children, according to Gaza's health ministry.
