Fears are growing for medical staff working at Al Shifa hospital after an organization that broadcasts messages from Gaza clinicians on social media revealed that they haven't had any communication with staff since Tuesday evening.

Al Shifa has become the main target of the incursion into the territory by Israeli forces, who say Hamas fighters located the "beating heart" of their operations in a headquarters in tunnels beneath it. Hamas has denied this, but on Wednesday, Israel said it had entered the hospital and had located Hamas's operational center inside, along with a cache of weapons.

They added that there had been no fighting and no friction with civilians, patients or staff.

But the situation at the hospital has stoked international alarm, with fears growing over the fate of thousands of people inside. Dr Omar Abdel Mannan, co-founder of Gaza Medic Voices, says the organization fears for the lives of staff and patients.

"We've been communicating with the doctors and surgeons since October ten on a daily basis," he said. "What I can say is that we have had zero communication since yesterday evening, which is extremely worrying. 

"The only thing that gave me some relief was hearing one of the doctors, Dr. Ahmed McLarty, speak to BBC News this morning (Tuesday) from Shifa. So that told me that not everyone is dead, which is what I feared, hearing that the Israeli Defense Forces had gone into the hospital and were attacking en masse."

Witnesses who spoke to Reuters news agency from inside the compound described a situation that appeared calm, if tense, as Israeli troops moved between buildings carrying out searches. Sporadic shooting was heard but there were no immediate reports of anyone hurt inside the grounds. 

The Israeli military released photos of a soldier standing beside cardboard boxes marked "medical supplies" and "baby food", at a location Reuters verified was inside Al Shifa. Other photos showed Israeli troops in tactical formation walking past makeshift tents and mattresses. 

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

Abdel Mannan says the hospital is now in a desperate state. "What we are seeing is a hospital that is no longer functioning as a hospital. It is a war zone. There are mass graves. They had to dig up mass graves to bury 200 dead. And they died yesterday. 

"There are premature babies that are no longer able to survive inside the incubators because it's a no longer working. So they're putting them together in cots, all 39 of them. We've had reports of six of them having died already and many more likely to die without sufficient aid, electricity and basic supplies."

Israel launched its campaign to wipe out Hamas after militants crossed into Israel on October 7 and rampaged through towns. Israel says 1,200 people were killed and some 240 captives taken in the deadliest day of its 75-year history. 

Since then, Israel has put Gaza's entire population of 2.3 million under siege, battering the crowded strip with air strikes. Gaza health officials, considered reliable by the United Nations, say more than 11,000 Palestinians are confirmed killed, around 40 percent of them children, and more are buried under the rubble. Israel has ordered the entire northern half of Gaza evacuated, and around two-thirds of residents are now homeless.

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