Hundreds of patients left al-Shifa hospital in Gaza City on Saturday morning, as Israeli officials stepped up their calls for civilians to head towards a “safe zone” in the south-west of the enclave.

The health ministry in Gaza said that Israel had ordered that the wounded and displaced be moved from al-Shifa, the largest medical facility in Gaza, and that those that were able to leave the hospital had begun to do so.

The Israeli army denied that it had ordered the patients or medical teams to leave, and said it had “acceded to the request” of the director of the hospital to enable Gazans who wanted to leave to do so.

Al-Shifa, which Israel says sits on top of a dense network of underground tunnels housing Hamas command centres, has become one of the main focuses of Israel’s three-week long ground offensive, triggering fears for the patients and people sheltering at the facility.

Hamas has denied using al-Shifa for military purposes and described the claims as an Israeli excuse to take over the hospital.

Israel has released footage of what it said was a tunnel shaft at al-Shifa but said on Friday that it would take time to prove that the site was a command centre. The footage could not be independently verified.

Later on Saturday, the head of UNRWA, the UN agency for Palestinian refugees, said that it had received “horrifying images and footage of scores of people killed and injured” after the UN school in Al Fakhoora where they were sheltering was struck.

“These attacks cannot become commonplace, they must stop,” Philippe Lazzarini wrote on social media site X. “A humanitarian ceasefire cannot wait any longer.”