For more than two weeks, Israeli forces have been carrying out an offensive in northern Gaza — a move the United Nations human rights office said appears to be cutting the region off from the rest of the Gaza Strip.

Palestinian and UN officials have specifically expressed concern over dire shortages of food and medicine after the Israeli army launched the new military operation, sending tanks into Jabalia and obstructing humanitarian aid deliveries.

Roughly 400,000 Palestinians remain in the region, according to UN estimates, as Israeli strikes in the north continue to rain down on civilians taking shelter in areas that include schools and makeshift tent camps. 

While many Palestinians hoped to see an end to the more than yearlong war, especially after the Israeli military killed Hamas leader Yahya Sinwar this week, military operations in the region only escalated a day after his death was announced.

The situation in the north continues to deteriorate as the Israeli military appears poised for a sustained ground incursion. CBC looks at four key factors:

• Food and humanitarian aid.
• State of hospitals.
• Towns isolated, movement blocked.
• International condemnation.

Food and humanitarian aid

Little aid is reaching northern Gaza, as humanitarian groups and officials of Palestinians raise concerns about the risk of famine.

Tedros Adhanom Ghebreyesus, the director general of the World Health Organization (WHO), said Wednesday that humanitarian groups have been unable to reach northern Gaza to provide food and medical supplies.

The UN said the operation cut off all aid deliveries through crossings in the north between Oct. 2 and Oct. 15, when a "trickle" was allowed in.There was barely any food left to distribute, and most bakeries in northern Gaza would be forced to shut down within days without additional fuel, the UN's humanitarian agency said Thursday.

WATCH | WHO on latest Israeli military operation in northern Gaza: 

Escalating violence in northern Gaza blocking humanitarian missions, WHO director says

WHO director general Tedros Adhanom Ghebreyesus said Wednesday that humanitarian groups have been unable to reach northern Gaza to provide food and medical supplies as Israeli troops press on in the region for nearly two weeks.

Data from Cogat, the Israeli government body that oversees aid and commercial shipments, shows that private sector trucks getting through have slowed down considerably. On Oct. 1, 54 trucks of "private sector" deliveries were sent in — the last significant shipment of commercial goods. Between Oct. 8 and Oct. 10, another 17 were recorded, bringing October's average to five trucks a day.

The Integrated Food Security Phase Classification (IPC), an initiative involving UN agencies, national governments and aid groups that sets the global standard on measuring food crises, said Israel's latest evacuation orders "have significantly disrupted humanitarian operations, and repeated displacements have steadily worn down people's ability to cope and access food, water and medicine, deepening the vulnerability of entire communities."

Roughly 86 per cent of the people across Gaza are experiencing high levels of acute food insecurity, according to an IPC analysis. That includes nearly 133,000 people facing famine, a number the IPC says is expected to double in coming months. 

Samih Motaz Fayez Ayoub says he cannot leave Jabalia Camp, where he is currently taking shelter with his wife and family. He said people there are on whatever food remains in the region.

"Life essentials do not exist. We're continuing to live without life essentials," Ayoub told CBC News.

Since Israel's military assault on Rafah in May, UN aid deliveries on that route have slumped, because the lack of security made them increasingly difficult to organize, UN relief agencies have said. 

The UN then relied heavily on a route bringing supplies via Jordan through Israel to a crossing at Gaza's northern tip. But shipments were halted after Israel introduced a customs rule on some of the aid, a move reported by Reuters this month.

On Wednesday, Cogat said 50 trucks entered northern Gaza. The agency says it does all it can to ensure enough aid enters the coastal enclave. It rejects allegations Israel has blocked supplies.

But Ismail Al-Thawabta, the director of the Hamas-run Gaza government media office, said Israeli comments about allowing aid into the enclave were misleading. He said the Israeli military has maintained a comprehensive siege on the far north of Gaza for more than 170 consecutive days, closing all humanitarian access points. 

"What is happening in northern Gaza is genocide and ethnic cleansing, destruction of houses, residential districts, roads, hospitals, schools, mosques and infrastructure as part of a displacement plan," said Thawabta. 

Israel has denied the evacuation orders are part of a systematic clearance plan, saying they have been issued to ensure people's safety and separate them from militants.

State of hospitals

Hospitals in northern Gaza are close to collapse, according to Palestinian health officials, as calls have grown for a humanitarian corridor for three of the region's hospitals: Kamal Adwan Hospital, the Indonesian Hospital and Al-Awda Hospital. 

Dr. Mahmoud Abu Amsha, head of the emergency department at Kamal Adwan Hospital, called for "urgent intervention."

"Northern Gaza is dying … there is no food and we're struggling with water scarcity," Abu Amsha told CBC News on Tuesday. 

Doctors have refused to leave their patients despite evacuation orders from the Israeli military.

Hussam Abu Safiya, director of the Kamal Adwan Hospital, called on the international community, the Red Cross and the World Health Organization to help open up a corridor for the region's health-care system to access fuel, medicine, supplies and food. 

Abu Safiya said there are more than 300 health-care workers at his hospital, which can't even provide them a meal to allow them to continue treating patients.

At Kamal Adwan Hospital, medics had to replace children in intensive care with more critical cases of adults badly wounded by Israeli airstrikes on Thursday on a school sheltering displaced Palestinians in Jabalia, which killed 28 people.

The escalation in the north also comes as a second round of the polio vaccine campaign is underway, with UN and Palestinian officials voicing concern about the viability of the campaign in northern Gaza. The campaign, which began Monday in central Gaza Strip, is set to move to the south and then to the north, accompanied by agreed-upon humanitarian pauses.

Philippe Lazzarini, head of the UN Palestinian refugee agency UNRWA, said on X that the Thursday attack on the school was the third on an UNRWA facility this week. He said the agency has lost a total of 231 team members in the past year of fighting.

Towns isolated, movement blocked

Israeli forces have isolated northern towns and blocked movement within those towns.

So far, the military has effectively isolated the towns of Beit Hanoun, Jabalia and Beit Lahiya from Gaza City.

On Friday, the Israeli military said it had sent another army unit to support forces operating in Jabalia.

Residents of Jabalia said Israeli tanks had reached the heart of the camp, using heavy air and ground fire, after pushing through suburbs and residential districts.

The escalation of Israel's Jabalia operation came a day after it said it had killed Hamas chief Yahya Sinwar.

WATCH | Sinwar killed by Israeli military in Rafah: 

Hamas leader Yahya Sinwar killed in Gaza, Israel confirms

Israel says its soldiers have killed top Hamas leader Yahya Sinwar in a battle in Gaza. Sinwar was a chief architect of last year's Oct. 7 attacks in southern Israel that triggered the war in Gaza and the escalating conflicts in the Middle East.

Residents in Jabalia said Israeli forces blew up clusters of houses firing from the air, from tanks and by placing bombs in buildings then detonating them remotely.

At least 350 Palestinians have been killed in the latest offensive in Jabalia and nearby areas, Palestinian health officials said on Wednesday.

Jonathan Crickx, a spokesperson for UNICEF Palestine, says most of the Palestinians in northern Gaza have been displaced up to 10 times. 

"Most of those people are moving with only what they have on their back, some clothes, maybe a little bag, and they are moving to where? Because there is no place safe in the Gaza Strip today," Crickx told CBC News.

He described the situation as "absolutely horrific."

"I was even in areas which are not as affected by the reduction of available supplies as the north is. I've been watching children climbing on a huge pile of garbage and digging into it, and with rats running around," he said.

Northern Gaza, which had been home to well over half of 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. 

That's after the Oct. 7, 2023, attacks on Israeli towns by Hamas-led fighters killed 1,200 people and captured 250 hostages.

Since then, more than 42,000 Palestinians have been killed and nearly 100,000 have been injured, according to the latest figures supplied by the Health Ministry in Gaza. As a result of the ongoing bombardment, hundreds of thousands of residents have come back to ruined northern areas. 

Muhammad Khalif says he will not leave Beit Lahiya as Israeli troops close in on the north.

"What concerns us is the rockets, the strikes. We don't sleep at night out of fear and terror," Khalif told CBC News.

"I want to tell the world this is enough, it's seriously enough. Enough terror, enough fear, enough hunger. We've drowned in blood."

Senior Hamas official Basem Naim said the latest Israeli offensive in northern Gaza amounted to a "very tight, suffocating siege" unlike others.

"It is much more brutal and aggressive [than previous operations]. It is directly targeting the civilian residential houses and homes," Naim told Reuters.

The Israeli military said it had killed dozens of militants in close-quarters combat on Thursday and carried out aerial strikes and dismantled military infrastructure. The army didn't provide evidence and CBC is unable to verify death tolls in the area, as foreign journalists are not allowed into the Gaza Strip and CBC's freelance videographer in southern Gaza is not allowed into Jabalia.

International condemnation

Israel's intense military operation in the north has sparked outrage and condemnation among Western countries, including Canada and the U.S., which have expressed concern over the humanitarian situation in the region.

Canada notably toughened its tone with Israel on Wednesday, condemning strikes on civilian infrastructure in Gaza and United Nations peacekeepers in Lebanon, and demanded the attacks stop immediately.

"These are unacceptable and must immediately stop," said a statement issued by Foreign Affairs Minister Mélanie Joly and International Development Minister Ahmed Hussen.

"The increasingly dire humanitarian situation is unacceptable and continues to deteriorate due to a significant decrease of aid allowed into Gaza ... the Palestinian civilian population has been displaced countless times, with nowhere safe to go and is unable to meet its most basic needs," it said.

Canada has largely supported Israel's military campaign in Gaza and Lebanon, but like some allies it is starting to express concern about a humanitarian disaster. It reiterated calls for an immediate ceasefire while also condemning attacks by both Hamas and Hezbollah on Israel.

WATCH | U.S. threatens to curtail military aid to Israel:

Israel says it's letting more aid into Gaza after U.S. threatens to curb military support

Israel has released footage it says shows 50 aid trucks crossing into northern Gaza where its troops have stepped up operations against Hamas fighters. The U.S. has threatened to curtail military aid to Israel if it doesn’t dramatically improve Gaza’s humanitarian situation.

This week, the United States issued one of its strongest warnings to Israel, telling the country it must take steps to improve the humanitarian situation in northern Gaza in 30 days or face potential restrictions on U.S. military aid.

In May, International Criminal Court (ICC) prosecutors asked the court to issue an arrest warrant for Israeli Prime Minister Benjamin Netanyahu, saying they suspected Israeli authorities had used "the starvation of civilians as a method of warfare."

Israeli authorities have denied this, saying they facilitate food deliveries despite challenging conditions. They have filed two official challenges to the ICC, contesting the legality of the prosecutor's request and the court's jurisdiction.