An Israeli self-propelled howitzer
An Israeli self-propelled howitzer along the border with Gaza near Sderot in southern Israel. AFP

Battles raged in Gaza on Saturday as Israel's army said it expanded ground operations after intensifying its bombardment of the Palestinian territory three weeks after the deadliest attack in the country's history.

The United Nations warned of a looming "unprecedented avalanche of human suffering" inside the Gaza Strip, after weeks of relentless Israeli bombing, while the General Assembly called for an "immediate humanitarian truce".

"We are confronting an Israeli ground incursion in Beit Hanoun (in the northern Gaza Strip) and east Bureij (in the centre) and violent engagements are taking place on the ground," Hamas's armed wing the Ezzedine al-Qassam Brigades said.

Israeli military spokesman Major Nir Dinar told AFP: "Our troops are operating inside Gaza as they did yesterday."

Israel launched its bombardment of Gaza after Hamas gunmen stormed across the border on October 7, killing 1,400 people, mostly civilians, and taking nearly 230 others hostage, according to Israeli officials.

The health ministry in the Hamas-run Gaza Strip said Friday that Israeli strikes had now killed 7,326 people, more than 3,000 of them children.

With tens of thousands of troops massed along the Gaza border ahead of an expected full-blown invasion, Israeli forces had also made limited ground incursions on Wednesday and Thursday nights.

"The ground forces are extending the ground operations tonight," military spokesman Daniel Hagari said late Friday.

The Israeli army said it had increased its strikes "in a very significant way", while the Ezzedine al-Qassam Brigades said on Telegram it responded with "salvos of rockets".

In overnight raids, Israeli fighter jets hit 150 "terror tunnels, underground combat spaces and additional underground infrastructure" and "several Hamas terrorists were killed", the army said on Saturday morning.

AFP live footage had shown air strike after air strike light up the night sky of northern Gaza late Friday as thick black smoke clouded the horizon.

In a bombed-out street in the Tal al-Hawa neighbourhood, 50-year-old Om Walid Basal said her apartment block had been destroyed by Israel.

"This was our house. We lived here just with our children. It was full of children," she said.

"Why are they bombing us? Why are they destroying our homes?"

Hamas insisted it was "ready" for an invasion.

"If (Prime Minister Benjamin) Netanyahu decides to enter Gaza tonight, the resistance is ready," Ezzat al-Rishaq, a senior member of the Hamas political bureau, said on Telegram on Friday.

"The remains of his soldiers will be swallowed up by the land of Gaza."

Hamas said all internet connections and communications across Gaza had been cut, and accused Israel of taking the measure "to perpetrate massacres with bloody retaliatory strikes from the air, land and sea".

Human Rights Watch also warned the near-total telecommunications blackout in Gaza risks providing cover for "mass atrocities".

The Palestinian Red Crescent said the communications outage had disrupted ambulance services.

"We have completely lost contact with the operations room in the Gaza Strip and all our teams operating there," it said on X, formerly Twitter.

Lynne Hastings, the UN humanitarian coordinator for the Palestinian territories, also stressed on X that "hospitals & humanitarian operations can't continue without communications".

Scotland's First Minister Humza Yousaf, whose inlaws are trapped in Gaza, voiced alarm at the communications shutdown.

"Telecommunications have been cut. We can't get through to our family who have been trapped in this war zone for almost 3 weeks," he wrote on X.

"We can only pray they survive the night."

The reports of ground fighting came after the UN General Assembly called on Friday for an "immediate humanitarian truce" in Gaza.

The non-binding resolution received overwhelming support, with 120 votes in favour, 14 against and 45 abstentions.

"Today the General Assembly declared a call: stop the war," the Palestinian ambassador to the UN, Riyad Mansour, told reporters at the United Nations headquarters in New York.

It was also welcomed by Hamas, but it was harshly criticised by Israel and the United States for failing to mention Hamas, with Israeli ambassador Gilad Erdan calling it an "infamy".

Washington had earlier said it supports a "humanitarian pause" so aid can get into Gaza.

Israel's bombardment has displaced more than 1.4 million people inside the crowded territory, according to the UN, even as supplies of food, water and power to Gaza have been almost completely cut off.

And Israel has blocked all deliveries of fuel, saying it would be exploited by Hamas to manufacture weapons and explosives.

UN Secretary-General Antonio Guterres warned that misery was "growing by the minute".

"I repeat my call for a humanitarian ceasefire, the unconditional release of all hostages, and the delivery of life-saving supplies," Guterres said.

"Without a fundamental change, the people of Gaza will face an unprecedented avalanche of human suffering."