Israeli forces have ordered Palestinians sheltering at one of the last functioning hospitals in Gaza to evacuate from the complex, raising fears that troops will attempt to storm a facility crowded with thousands of people, some of whom have been shot at as they tried to flee, according to doctors there.

The Israeli military accused Hamas on Wednesday of conducting military activity inside the grounds of the hospital, the Nasser Medical Complex in Khan Younis, and alleged that the complex “was used to hold hostages.”

Israel’s claims could not be independently verified, but they signaled its intensifying focus on the hospital as Israeli forces try to root out Hamas fighters from the southern city. Previous Israeli warnings to evacuate hospitals, including Al-Shifa, the largest in Gaza, have often preceded military raids on the facilities.

“We demand the immediate cessation of all military activity in the area of the hospital and the immediate departure of military operatives from it,” the Israeli military said in a statement. It called for civilians sheltering at the hospital to leave for “safer spaces” in southern and central Gaza. The statement did not call on patients or medical workers to leave the hospital.

Gazans have said that Israeli forces regularly fire on areas where they have told people to flee, leaving nowhere in the enclave safe. Adding to the terror of those inside the hospital, Israeli forces fired on people who tried to leave the compound, with some being killed or injured, according to two doctors interviewed on Tuesday.

“The situation is very dangerous,” said Khaled Al-Serr, a general surgeon at the hospital. He said that the Israeli military had indicated just a day earlier that the hospital, which has been surrounded by Israeli ground forces for weeks, was safe.