It was unclear where those who left the complex could find safety, as Israel’s military has often bombarded areas of Gaza that it had previously said were safe. Israeli leaders have also vowed to invade Rafah, the southernmost city in Gaza, which is sheltering more than a million people.
Inside the hospital, some medical staff were packing their belongings and preparing their families to flee.
“We are all scared,” said Dr. Mohammad Abu Moussa, a radiologist at Nasser. He added that even though he worried about an assault on the hospital, he and his wife had made the difficult decision to stay for now. They and their two surviving children — a third was killed in an airstrike in October — have been staying at the hospital for weeks.
“I have no other choice,” Dr. Abu Moussa said. “I don’t have anywhere to go in Rafah, and I have young children and they can’t walk long distances like that.”
Hanin Abu Tiba, 27, an English teacher sheltering at the hospital, described dire conditions inside, with food running out and aid convoys all but unable to deliver supplies. In text messages overnight, she said that she had seen an Israeli military vehicle outside the hospital gate.
“I’m terrified to leave the hospital and get shot,” she said. But inside the complex, she said, “the electricity is cutting out, and the water, and the canned food is almost gone. We don’t know what to do.”
Throughout the four-month war, the Israeli military has stormed other Gaza hospitals, detaining medical staff, according to the health ministry.
“We are very concerned about the situation developing at Nasser Hospital in Khan Younis,” the medical aid group Doctors Without Borders said on social media on Wednesday. It called on Israeli forces “to ensure the safety of all medical staff, patients and displaced people.”
Rawan Sheikh Ahmad and Aaron Boxerman contributed reporting.