Witnesses claimed Israeli forces stormed Gaza’s largest hospital on Wednesday and were examining its rooms and basement, capping a days-long blockade that sparked global concern over the fate of thousands of patients trapped within.

The Al Shifa hospital in Gaza City has been the primary target of Israeli troops, who claim Hamas militants have found the “beating heart” of their operations at a headquarters in tunnels beneath it, something Hamas disputes.

After killing combatants in a confrontation outside, Israel said its soldiers discovered undisclosed weapons and “terror infrastructure” within the hospital area. They said there was no violence or conflict with people, patients, or personnel once inside.

Witnesses who spoke to Reuters from inside the property on Wednesday reported a peaceful, yet stressful, scene as Israeli forces went between buildings conducting inspections. There was sporadic firing, but there were no early reports of anybody being injured inside the premises.

The Israeli military provided images of a soldier standing next to cardboard boxes labeled “medical supplies” and “baby food” at a location inside the facility that Reuters confirmed. Other images showed Israeli forces traveling in tactical order past improvised tents and beds.

World attention has been focused on the fate of hundreds of patients trapped inside without power to operate basic medical equipment, and thousands of displaced civilians who had sought shelter there. Gaza officials say many patients including three newborn babies died in recent days as a result of Israel’s encirclement of the facility.

“Before entering the hospital our forces were confronted by explosive devices and terrorist squads, fighting ensued in which terrorists were killed,” the Israeli military said.

“We can confirm that incubators, baby food and medical supplies brought by IDF tanks from Israel have successfully reached the Shifa hospital. Our medical teams and Arabic speaking soldiers are on the ground to ensure that these supplies reach those in need,” it said.

A senior military official said: “IDF soldiers have already found weapons and other terror infrastructure. In the last hour, we saw concrete evidence that Hamas terrorists used the Shifa hospital as a terror headquarter.”

Hamas called the claim that weapons were found “a continuation of the lies and cheap propaganda through which (Israel) is trying to give justification for its crime aimed at destroying the health sector in Gaza”.

Dr Ahmed El Mohallalati, a surgeon, told Reuters by phone on Wednesday morning that staff had hid as the fighting unfolded around the hospital overnight. As he spoke, the sound of what he described as “continuous shooting from the tanks” could be heard in the background.

“One of the big tanks entered within the hospital from the eastern main gate, and they were, they were they just parked in the front of the hospital emergency department,” he said.

The Israelis had told the hospital administration in advance that they planned to enter, he said. By mid morning, he and other staff had yet to receive instructions from the troops, although the soldiers were “metres away” from them.

“They have been moving between the buildings where the troops can be seen, within the hospital areas. So, it’s getting more and more close to our building. We don’t know what they want exactly,” he said. “The tanks are continuously moving within the hospital area.”

After five days during which he said the hospital had come under repeated Israeli attack, it was a relief at least to have reached an “end point”, with troops now inside the grounds instead of outside shooting in, he said.

He was worried about the fate of his patients but unconcerned about potential clashes in the compound, saying Israeli claims that there were fighters inside had been a “big lie”.

The Israelis had used “all kinds of weapons” and “targeted the hospital directly” during their siege, he said, describing a large hole that had been blasted through the wall of a room in an outpatient building.

Another witness inside the hospital, reached by telephone, said tanks had entered the compound at 3:00 a.m. The Israeli troops dismounted and spread out in the yard, and began searching the basement and entering buildings.

“It was very dangerous looking from the glass window. The administration of the hospital told us the occupation army informed them they wanted to search us and search room by room. I am very scared,” the man said, asking that his name be withheld for fear of Israeli reprisals.

“There was no shooting because there were no gunmen inside the facility. The soldiers were acting freely as were people inside the hospital, the doctors, the wounded and the displaced,” the man said. He later told Reuters that gunfire could occasionally be heard.