Special forces, supported by infantry and tanks, conducted a “precise operation” based on intelligence that the hospital was again being used by Hamas leaders, and were fired upon when they entered the compound, the military said.

“We apprehended more than 200 terrorist suspects that are now being questioned. We eliminated more than 20 terrorists inside the hospital compound,” said spokesperson Rear Admiral Daniel Hagari.

One Israeli soldier was killed in the fighting, he said.

“Hamas tried to reestablish its base in the hospital and use it as a shelter for terrorists on the run. We will not allow this and will attack and continue to attack any place Hamas tries to reestablish its grip,” Hagari said.

Al Shifa, the Gaza Strip’s biggest hospital before the war, is now one of the only healthcare facilities that is even partially operational in the north of the territory, and is also housing hundreds of displaced civilians.

Palestinian health authorities said the operation caused multiple casualties and set off a fierce fire in one of the buildings.

The Israeli military issued footage of the operation showing soldiers in the hospital compound engaged in gunfights as well as weapons and money it said it found in the hospital. Reuters could not independently verify the video.

The military said troops had been instructed on the importance of operating cautiously as well as on measures to be taken to avoid harm to patients, civilians, medical staff and medical equipment, and said patients were not required to evacuate.

Hamas said in a statement the Israeli military had committed a new crime by directly targeting the hospital buildings without caring about patients, medical staff or displaced people in it.

Gaza’s Hamas-run health ministry said a fire broke out at the entrance of the hospital complex, causing cases of suffocation among displaced women and children sheltering in the hospital. It said communication had been cut off, with people trapped inside the surgery and emergency units of one of the buildings.

Israel came under fierce criticism last year when troops first raided the hospital, where they uncovered tunnels they said were used as command and control centres by Hamas. Hamas and medical staff deny the hospital has been used for military purposes or to shelter fighters.