JERUSALEM (Reuters) - Gaza's besieged people had barely any communications with the outside world on Saturday as Israeli jets dropped more bombs and military chiefs said a long-threatened ground offensive against Hamas militants running the Palestinian enclave was gearing up.
"This war has stages and today we are moving to the next stage. Our forces are currently operating on the ground in the Gaza Strip," said Israeli armed forces chief Herzi Halevi.
Israel has blockaded and bombarded Gaza for three weeks after the Islamist group Hamas' Oct 7 assault killed 1,400 Israelis in the deadliest day of the nation's 75-year history.
Western countries have generally backed what they say is Israel's right to self defence but there has been mounting international concern over the toll from the bombing and growing calls for a pause to allow aid to reach the people of Gaza.
Health authorities in the Hamas-ruled Gaza Strip of 2.3 million people say 7,650 Palestinians have been killed in Israel's ensuing campaign to obliterate the militants.
With many buildings reduced to rubble and shelter hard to find, Gazans are short of food, water, fuel and medicines. Their plight got worse from Friday night when phone and internet services were cut - followed by heavy bombing through the night.
"God help anyone under the rubble," said one Gaza journalist, who spent a terrifying night in a stairway building watching "belts of fire" as bombs fell and Israeli forces appeared to exchange fire with Palestinian fighters.
Without mobile phones, no one could call ambulances and emergency services anyway were short of fuel, he said, adding that desperate people were turning to the police when they could be found to use their walkie-talkies to seek help.
Though there was no indication of an invasion en masse, Israel said troops sent into Gaza on Friday night were still in the field, focusing on infrastructure including the extensive tunnel network built by Hamas.
"We attacked above the ground and underground, we attacked terror operatives of all ranks, everywhere," Defence Minister Yoav Gallant said.
Israel again told Gazans to move away from the north where it says Hamas is hiding under civilian buildings. Palestinians say nowhere is safe, with bombs also smashing homes in the south of the densely populated territory.
"A humanitarian catastrophe is unfolding in front of our eyes," UN Secretary-General Antonio Guterres said.
MUSK OFFERS SATELLITE HELP
Various global aid agencies said they could not contact their staff in Gaza. But a representative from the International Committees of the Red Cross and Red Crescent in Gaza got an audio message out.
William Schomburg said medics were working around the clock while also dealing with personal tragedies. "I spoke to one doctor who had lost his brother and cousin the night before," he told the BBC broadcaster in a clip the ICRC posted on X.
Billionaire entrepreneur Elon Musk offered help from his Starlink satellite network to support communications in Gaza for internationally recognised aid organisations.
Video from the Israeli side of the heavily fortified fence showed explosions in Gaza sending up clouds of smoke among a line of ruined buildings.
Al Jazeera, which broadcast live satellite TV footage overnight showing frequent blasts, said air strikes had hit areas around the enclave's main hospital Al Shifa.
Israel had accused Hamas of using the hospital as a shield for tunnels and operational centres, which the group denied.
Reuters could not verify reports of strikes by the hospital.
An Al Jazeera correspondent said Palestinians were taking the dead and injured to hospital in their cars.
Hamas said on Saturday that it had been about to reach an agreement with Israel over the more than 200 hostages it has in Gaza, but Israel "stalled" on that.
Israel's Halevi said in his televised message "we will do everything we can" to recover the hostages but the main military spokesman dismissed the reports of an imminent deal, saying Hamas was "cynically" attempting to sway public opinion.
Israel said rockets were still being fired at it from Gaza and released footage of its forces, including a column of tanks, inside the territory.
Jets killed the head of Hamas' aerial wing, Asem Abu Rakaba, a key figure in the Oct 7 attack, it said.
REGIONAL 'TIME BOMB'
Jets also struck 150 underground targets in north Gaza, including Hamas tunnels, underground combat spaces and other underground infrastructure, killing others from the group.
The armed wing of Hamas, the al-Qassam brigades, said its fighters were fighting Israeli troops in Gaza's northeastern town of Beit Hanoun and in the central area of Al-Bureij.
"Al-Qassam Brigades and all Palestinian resistance forces are fully prepared to confront the aggression with full force and thwart the incursions," it said.
The United States and other Western countries have offered strong support to Israel but urged it to hold off on a ground offensive for fear of high casualties among Palestinians and a widening conflict.
Hamas is backed by Iran, which also supports militias in Lebanon, Syria, Iraq and Yemen. U.S. troops have come under fire from Iran-backed groups in Iraq and Syria. Washington has been moving more military assets to the region.
The Israeli military reported a new exchange of fire on the border with Lebanon on Saturday, the latest in what have been the most serious clashes on the border since 2006. Israel's neighbour Egypt said drones fell on the country on Friday.
"The region will becoming a ticking time bomb that impacts us all," warned Egypt's President Abdel Fattah al-Sisi.
The crisis brought hundreds of thousands of pro-Palestinian demonstrators out in cities around Europe, the Middle East and Asia on Saturday.
"This is not about Hamas. This is about protecting Palestinian lives," said marcher Camille Revuelta in London.