Updated 10,40am

Israel pounded the Hamas-run Gaza Strip with air and artillery strikes on Saturday after an intense night of attacks when it said 150 "underground targets" were hit.

No official toll was immediately given, but a Gaza civil defence official told AFP a "large number" of dead was feared from one of the most intense nights of attacks in Israel's war in response to the Hamas attacks on October 7.

Multiple reports indicated that internet and telephone networks in Gaza were cut off.  

Turkey's president, Recep Tayyip Erdogan, called on Israel to "immediately stop this madness." 

"The Israeli bombardments on Gaza intensified last night and once again targeted women, children and innocent civilians and worsened the ongoing humanitarian crisis," Erdogan said on X, formerly Twitter.

Israel has been building up to a ground invasion since Hamas fighters crossed the border and killed 1,400 people, mainly civilians, and took more than 220 hostages, according to Israel.

The Hamas-controlled health ministry says that more than 7,300 people have been killed in Gaza, including about 3,000 children.

A thick haze of smoke covered Gaza and southern Israel after the night of heavy bombardment, according to AFP correspondents.

More air raids and artillery shelling were reported after daybreak but less intense than during the night.

The Gaza civil defence official told AFP: "There are a large number of martyrs and a large number of survivors under the rubble, and we cannot reach them," the official said.

'Why are they bombing us?'

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

In a bombed-out street in the Tal al-Hawa neighbourhood, 50-year-old Om Walid Basal asked why her apartment block had been bombed 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?"

Residents told AFP the Indonesian Hospital in Beit Lahia was damaged by a tank shell and there was major damage around Al-Shifa hospital, Gaza's biggest hospital where thousands of people have taken refuge.

The Israeli army has charged that Hamas fighters were using hospitals in Gaza to "wage war" against Israel.

Paramedics said many people were feared dead after an apartment block and nearby houses were destroyed at dawn at the Beach camp.

'Big plan'

Since the October 7 attacks, Israel warned about 1.1 million people in northern Gaza that they should move to the south.

The Israeli military believes the Hamas leadership and its main infrastructure is concentrated in the north.

An unnamed officer quoted by an Israeli military account on X, the former Twitter, said: "We are bombarding Gaza with an intensity that has never been seen before in the Gaza Strip. From the air, from the ground or from the underground -- the IDF (Israeli army) will eliminate every senior or junior terrorist and all Hamas terrorist infrastructure."

Just before the latest strikes, a senior Israeli officer said the raids did not mark the start of the ground invasion.

"When the war starts, we will know it we will hear it, we will see it," said Colonel Golan Vach, head of Israel's search and rescue operation.

"It is going to be lethal and it is going to take time. What you saw in the past two days of small forces movement inside and out of Gaza was for other reasons. Not so much operational but part of the big plan."

More than eight hours of night attacks on the besieged Palestinian territory into the early hours of Saturday rattled windows and shook the ground in Ashkelon 10 kilometres (6.5 miles) from the Gaza border.

Smoke and the pungent smell of burning material filled the air in the city that has been mainly evacuated since the attacks, an AFP correspondent said.

Israeli military jets continued to fly overhead Saturday and regular concussive booms could be heard coming from Gaza.

Internet cut

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 that the near-total telecommunications blackout in Gaza risks providing cover for "mass atrocities".

The Palestinian Red Crescent meanwhile said ambulance services had been disrupted.

"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 occupied Palestinian territory, also said on X that Gaza "has lost contact with the outside world", cautioning that "hospitals & humanitarian operations can't continue without communications". 

UN truce call

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

The nonbinding resolution received overwhelming support and was 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 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, 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 in a statement.

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

Jordan's foreign minister warned on X that an Israeli ground invasion of Gaza would spell a "catastrophe of epic proportions" for the territory for years to come.