Israel-Hamas LIVE: Israeli troops continue search of Al-Shifa hospital as UN warns it cannot distribute aid in Gaza

The Israeli army said Friday it had killed 'at least five terrorists' during an operation in Jenin, in the occupied West Bank.

Israeli forces carried out an operation in a refugee camp in the city overnight, and the military said in a statement that, 'In total, at least five terrorists were killed.'

The two telecoms companies in Gaza said all services in the territory were down as energy supplies had run out. Israel refuses to allow fuel imports into Gaza, saying Hamas could use them for military purposes.

With communications out and in the absence of fuel, the U.N. agency for Palestinian refugees, UNRWA, said it was impossible to coordinate humanitarian aid truck convoys.

'If the fuel does not come in, people will start to die because of the lack of fuel. Exactly as from when, I dont know. But it will be sooner rather than later,' said UNRWA Commissioner-General Philippe Lazzarini.

'When you have a blackout and you cannot communicate with anyone anymore... that triggers and fuels even more the anxiety and the panic.'

Israeli Prime Minister Benjamin Netanyahu alleged hostages may even have been held at the medical facility.

'We had strong indications that they were held in the Shifa Hospital, which is one of the reasons we entered the hospital,' he told 'CBS Evening News'.

'If they were (there), they were taken out,' he said.

Allegations about the hospital have not been verified, and on Friday communications with the Gaza Strip were severed once again.

Israeli troops for a second day searched Al-Shifa Hospital in the north for traces of Hamas.

They displayed what they said were a tunnel entrance and weapons found in a truck inside the compound. But the military has yet to release evidence of a central Hamas command centre that Israel has said is concealed beneath the complex. Hamas and staff at the hospital, Gaza's largest, deny the allegations.