GAZA - Israel pounded northern Gaza and said it was "extending" its ground operation late Friday amid UN warnings of an "avalanche of human suffering" in the battered Palestinian territory.
"Following the series of strikes of the last days, the ground forces are extending the ground operation tonight," military spokesman Daniel Hagari told reporters.
His announcement followed two straight nights of tank incursions into Gaza.
Earlier, the military said it had increased its strikes "in a very significant way", as AFP live footage captured intense bombardment of northern Gaza.
The armed wing of the Islamist group Hamas said it responded with "salvos" of rockets aimed at Israel.
Hamas said all internet connections and communications across the territory had been cut, and accused Israel of taking the measure "to perpetrate massacres with bloody retaliatory strikes from the air, land and sea".
Israel has heavily bombarded Gaza since Hamas gunmen stormed across the border on October 7, killing 1,400 people, mostly civilians, and kidnapping over 220 others, according to Israeli officials.
"Salvos of rockets in the direction of the occupied territories (Israel) in answer to the massacre of civilians," Hamas's armed wing, the Ezzedine al-Qassam Brigades, said on its Telegram channel.
The Hamas-run health ministry said Friday Israeli strikes on Gaza had now killed 7,326 people, mainly civilians and many of them children.
UN chief Antonio Guterres warned that Gaza faces "an unprecedented avalanche of human suffering" because of the lack of food, water and power during Israeli bombing in response to the October 7 attack.
"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.
"Misery is growing by the minute. Without a fundamental change, the people of Gaza will face an unprecedented avalanche of human suffering."
The UN agency for Palestinian refugees had earlier warned that "many more will die" in Gaza from catastrophic shortages after nearly three weeks of bombardment by Israel.
The UN human rights office also raised the alarm over "war crimes" being committed as the Israel-Hamas conflict raged into its 21st day.
Concern is growing about regional fallout from the conflict, with the United States warning Iran against escalation while striking facilities in Syria it says were used by Iran's Islamic Revolutionary Guard Corps and others.
Israel's military on Friday accused Hamas of using hospitals in Gaza as operations centres for directing attacks.
"Hamas wages war from hospitals," in the territory, military spokesman Daniel Hagari said, and alleged the group was also using fuel stored in these facilities for its operations.
The allegation was swiftly denied by a senior Hamas official who said it had "no basis in truth".
Israel has cut supplies of food, water and power to Gaza, notably blocking all deliveries of fuel saying it would be exploited by Hamas to manufacture weapons and explosives.
"People in Gaza are dying, they are not only dying from bombs and strikes, soon many more will die from the consequences of (the) siege," said UNRWA chief Philippe Lazzarini.
"Basic services are crumbling, medicine is running out, food and water are running out, the streets of Gaza have started overflowing with sewage," he said of the densely populated territory where 45 percent of housing is reported to have been damaged or destroyed.
In Geneva, the UN human rights office raised the alarm over war crimes, saying "the atrocious attacks by Hamas... amounted to war crimes" but also pointing to Israel's Gaza bombardment.
"Nowhere is safe in Gaza. Compelling people to evacuate in these circumstances... and while under a complete siege raises serious concerns over forcible transfer, which is a war crime," spokeswoman Ravina Shamdasani said of Israel's order for northern Gaza residents to flee south.
- 'Nothing more than crumbs' -
A first tranche of critically needed aid was allowed in at the weekend, but since then only 74 trucks have crossed. Before the conflict, the UN says an average of 500 trucks were entering Gaza every day.
"These few trucks are nothing more than crumbs that will not make a difference," Lazzarini said, insisting Gaza needed a "meaningful and uninterrupted aid flow" and a "humanitarian ceasefire to ensure this aid reaches those in need".
His words echoed a call from EU leaders on Thursday for "continued, rapid, safe and unhindered humanitarian access and aid".
A first team of six medics from the International Committee of the Red Cross entered Gaza Friday via its Rafah crossing with Egypt, along with six aid trucks, the ICRC said.
Between the bombardments and the fuel shortages, 12 of Gaza's 35 hospitals have been forced to close, and UNRWA said it has had to "significantly reduce its operations".
With tens of thousands of Israeli troops massed along the Gaza border ahead of a widely expected ground offensive, the army said it had staged another brief ground incursion into Gaza, the second in as many days.
"We carried out a ground operation in central Gaza... as part of preparations for the coming stages of the war," the army's Hagari said. The first incursion had targeted northern Gaza.
Hamas said Israel had tried to stage "a large-scale amphibious operation on Rafah's coast" in southern Gaza at dawn but it had been thwarted, and the soldiers had "fled by sea, leaving behind a quantity of weapons".
Israel confirmed the operation, saying troops had struck "Hamas military infrastructure and... a compound" used by Hamas militants.
- 'Wherever we go, we will die' -
The army also updated to 229 the number of hostages held by Hamas, many of whom hold foreign passports, with their families frantic about their fate.
"I have never felt such a feeling of helplessness," said 23-year-old Ella Ben Ami whose parents were kidnapped. With recurring nightmares every single night, she says she feels "like the living dead".
Militants also fired rockets on Friday towards Tel Aviv. One struck the city, wounding three people, one moderately and two lightly, medics said.
Violence has also risen sharply in the occupied West Bank since the October 7 attacks, with more than 100 Palestinians killed and over 1,900 wounded.
Another four Palestinians were killed Friday during Israeli raids in the northern cities of Jenin and Qalqilya, the health ministry said.
By Adel Zaanoun