Doctors Without Borders has suspended operations in Gaza City because of the danger to its staff caused by the Israeli military’s ground offensive, the latest sign of the growing pressures on medical care in the territory.

The organization, which provides medical care, including treatment for malnutrition and severe trauma injuries, said on Friday that it had stopped activities in Gaza City and that Israeli tanks and military strikes had advanced within roughly a half mile of the group’s clinics there.

“We have been left with no choice but to stop our activities, as our clinics are encircled by Israeli forces,” Jacob Granger, the emergency medical coordinator in Gaza for Doctors Without Borders, said in a statement. “This is the last thing we wanted, as the needs in Gaza City are enormous.”

The charity made the announcement on the same day that the United Nations said four hospitals had been rendered unusable in the north of the territory over the past month, adding that an airstrike severely damaged one of them on the first day of the Israeli ground offensive. The Israeli military did not immediately respond to a request for comment.

Tarik Jasarevic, a spokesman for the World Health Organization, told reporters in Geneva on Friday that more hospitals in Gaza might have to suspend operations in the coming days because of a lack of supplies, including blood and blood bags.

A lack of fuel to run hospital generators has also been a persistent problem during the war, which was ignited by a Hamas-led attack on Israel on Oct. 7, 2023. Gaza’s health ministry said last week that unreliable supplies could make access to health care even harder.