Israeli forces widened their raid in northern Gaza, and tanks reached the north edge of Gaza City, pounding some districts of the Sheikh Radwan neighborhood and forcing many families to leave their homes, Reuters reported, citing residents.

In the early hours of Monday, an Israeli air strike killed three people and wounded 40 others when it hit some tents of displaced Palestinians inside Al-Aqsa Hospital in the central Gaza Strip city of Deir Al-Balah, where a million people were sheltering, medics said.

The Israeli military said it struck militants operating from a command center inside the compound, accusing Hamas of using civilian facilities such as hospitals for military purposes, which Hamas denies.

Residents said Israeli forces had effectively isolated Beit Hanoun, Jabalia, and Beit Lahiya in the far north of the enclave from Gaza City, blocking access between the two areas except upon permission for families willing to heed evacuation orders and leave the three towns.

Nine days into a major Israeli operation in northern Gaza, the Hamas-run Gaza government media office said Israeli strikes had killed around 300 Palestinians there. It said Israel's bombardment of civilian houses and displacement shelters was intended to force residents to leave Gaza once and for all, which Israel denies.

Later on Sunday, Israeli tank shelling killed at least 22 Palestinians at a school sheltering displaced families in Nuseirat camp in the central Gaza Strip, medics said.

The Hamas-run Gaza government media office said at least 15 children and women were among those killed in the school. It added that 80 other people were wounded.

Hours earlier, an Israeli air strike killed five children in the Shati refugee camp in Gaza City. The Palestinian official news agency WAFA and Hamas media said the children were playing near a cafe when they were killed by a missile fired from an Israeli drone.

The Israeli military did not immediately comment on the two reports.

"What's happening in northern Gaza is terrifying beyond words," acting UN aid chief Joyce Msuya said in a post on social media platform X.

"Attacks by Israeli forces are intensifying. Hospitals are forced to evacuate their patients. Essential supplies are running out. People forcibly displaced, cut off from aid, left to starve. The atrocities must end," she said.

U.S. Vice President Kamala Harris, citing UN reports that no food has entered northern Gaza in nearly two weeks, said on X that "Israel must urgently do more to facilitate the flow of aid to those in need."

"Civilians must be protected and must have access to food, water, and medicine. International humanitarian law must be respected," said Harris, the Democratic party's nominee in next month's presidential election.

While the main assault is on the north, Israel is also striking other areas across the Gaza Strip. The health ministry reported on Sunday that at least 34 people have been killed so far.

Many Jabalia residents posted on social media platforms, "We will not leave, we die, and we don't leave."

The northern part of Gaza, home to well over half the territory's 2.3 million people, was bombed to rubble in the first phase of Israel's assault on the territory a year ago, after the October 7 attacks on Israeli towns by militants who killed 1,200 people and captured 250 hostages.

After a year of Israeli assaults that killed 42,000 Palestinians, hundreds of thousands of residents have come back to ruined northern areas. More than a week ago, Israel sent troops back to root out fighters it said were regrouping for more attacks. Hamas denies fighters operate among civilians.

The escalation in northern Gaza has taken place alongside a huge Israeli air assault and ground campaign on a separate front in southern Lebanon against Hezbollah.

The Israeli military said in a statement on Sunday that forces operating throughout the Gaza Strip in the past 24 hours had attacked about 40 targets and killed dozens of militants.

"The forces of Division 162 continue to operate in the Jabalia region. In the last day, the forces killed dozens of terrorists and found explosives, weapons, grenades and other means of warfare in the region," it said.

The armed wings of Hamas, the Islamic Jihad, and smaller other factions said their fighters attacked Israeli forces in Jabalia and nearby areas with anti-tank rockets and mortar fire.

Palestinian and United Nations officials say there are no safe areas in Gaza. They have also voiced concerns over the severe shortage of food, fuel, and medical supplies in northern Gaza and said there is a risk of famine there.

(With input from Reuters)