Israeli forces launched another raid on the Gaza Strip's largest hospital early Monday, saying Hamas militants had regrouped there and had fired on them from inside the compound, where Palestinian officials say tens of thousands of people were sheltering.

The army last raided Shifa Hospital in November after claiming that Hamas maintained an elaborate command centre within and beneath the facility. The military revealed a tunnel leading to a bunker, as well as weapons it said were found inside the hospital, but the evidence fell short of the earlier claims, and critics accused the army of recklessly endangering the lives of civilians.

People sheltering in the hospital said Israeli forces backed by tanks and artillery had surrounded the medical complex early Monday and that snipers were shooting at people inside. They said the army raided a number of buildings and detained dozens of people.

“We're trapped inside,” said Abdel-Hady Sayed, who has been sheltering in the medical facility for over three months. “They fire at anything moving … doctors and ambulances can't move.”

Gaza's Health Ministry said the Israeli army was directing gun and missile fire at a building used for specialised surgeries. It said a fire broke out at the hospital's gate.

The ministry said around 30,000 people are sheltering at the hospital, including patients, medical staff and people who have fled their homes seeking safety.

Rear Adm. Daniel Hagari, the chief Israeli military spokesperson, said the army launched a “high-precision operation” in parts of the medical complex. He said senior Hamas militants had regrouped there and were directing attacks from the compound.

The army released a grainy aerial video of what it said were militants firing on its forces from inside the hospital, as well as video of a rocket-propelled grenade striking an armoured vehicle. It said its forces had detained around 80 people in the raid.

Hagari said the patients and medical staff could remain in the medical complex and that a safe passage was available for civilians who want to leave.

Israel accuses Hamas of using hospitals and other civilian facilities to shield its fighters, and the Israeli military has raided several hospitals since the start of the war, which was triggered by Hamas' October 7 attack into southern Israel.

Most of Gaza's medical facilities have been forced to shut down for lack of fuel and medical supplies, even as scores of people are killed and wounded each day in Israeli strikes. Israel's offensive has driven most of Gaza's 2.3 million people from their homes and the UN says a quarter of the population is starving.

The Gaza Health Ministry said at least 31,645 Palestinians have been killed in the war. The ministry doesn't differentiate between civilians and combatants in its count, but says women and children make up two-thirds of the dead.

Palestinian militants killed some 1,200 people in the surprise attack out of Gaza that triggered the war and took another 250 people hostage. Hamas is still believed to be holding about 100 captives, as well as the remains of 30 others, after most of the rest were freed during a cease-fire last year in exchange for the release of Palestinians imprisoned by Israel.

The United States, Qatar and Egypt have spent weeks trying to broker another cease-fire and hostage release, but the gulf between the two sides remains wide, with Hamas demanding guarantees for an end to the war and Israel vowing to continue the offensive until it dismantles the militant group.