Medics and rights groups on Tuesday called for the immediate opening of a humanitarian corridor from Gaza to allow the urgent evacuation of patients to hospitals in east Jerusalem.
Israel controls all points of departure from the Gaza Strip which has been battered by over a year of war between Israel and militants led by the Palestinian Islamist group Hamas.
Rare medical evacuations have been organised by international organisations or foreign countries in coordination with Israeli authorities.
But amid mounting casualties from the war, the East Jerusalem Hospitals Network and Physicians for Human Rights Israel (PHRI) called for the immediate reopening of the Gaza to east Jerusalem medical corridor, estimating that about 25,000 patients in Gaza were in need of urgent care.
Fadi Atrash, the director of the Augusta Victoria Hospital in east Jerusalem, said the reopening of the evacuation corridor "is essential to allow us to continue to provide vital treatments in hospitals in east Jerusalem, where we have both the space and the medical expertise".
Prior to the war, patients in Gaza who were in need of medical care unavailable in the Palestinian territory could be evacuated to hospitals in the Israeli-annexed east Jerusalem or the occupied West Bank, and in some cases in Israel.
But since the Gaza war broke out last year, that mechanism has been defunct.
During an exceptional evacuation of about 200 patients from Gaza in early November, the World Health Organization said about 14,000 people were awaiting medical evacuations.
Days later, Doctors Without Borders (MSF) said "Israeli authorities blocked, without explanation, the medical evacuation of eight children and their caretakers from Gaza who are in need of medical care, including a two-year-old with leg amputations, to the MSF hospital in Jordan".
"We strongly denounce this decision," it said.
On Tuesday, "31 patients and caregivers left Gaza" through the Kerem Shalom crossing between Gaza and Israel, COGAT, the Israeli Defence Ministry agency managing civil affairs in the Palestinian territories, said.
It added that the patients were to be transferred to Jordan and the United States for treatment.
World Health Organization Director-General Tedros Adhanom Ghebreyesus said in a post on X that the 31 comprised 11 children with cancer awaiting treatment and 20 companions.
"Thousands of patients across Gaza still need medical evacuations for life-saving medical care. We urge that all corridors be utilised for the safe transfer of patients outside the Gaza Strip," he said.
More than 105,000 people have been wounded in Gaza since the war erupted on October 7, 2023, according to figures from the territory's health ministry which the United Nations deems reliable.
Gaza's healthcare system has largely been decimated by the war, with only a handful of medical facilities now able to provide care.