At least 17 people have been killed in an Israeli strike on a school sheltering displaced Palestinians in central Gaza, as Israeli forces carried out attacks across the enclave.

Palestinian medical officials said the Israeli attack in the Nuseirat refugee camp killed mostly women and children, including an 11-month-old baby, and wounded 42 others.

The al-Awda Hospital, which received the casualties, said 13 children under the age of 18 and three women were among the dead.

The Israeli military claimed it targeted Hamas fighters inside the school, without providing evidence. Israel has carried out several strikes on schools sheltering displaced Palestinian families in recent months, often killing women and children.

Medical sources told Al Jazeera that at least 34 people have been killed in Israeli attacks across the besieged enclave on Thursday, as Israel bombarded central and southern Gaza and its troops continued a ground offensive and siege in the northern part of the Gaza Strip.

Some 400,000 people remain trapped in the widely ravaged area, mainly in Jabalia, Beit Hanoon, and Beit Lahiya.

Gaza’s Government Media Office said at least 770 Palestinians have been killed and 1,000 others wounded in the assault, which entered its 20th day on Thursday.

United Nations humanitarian officials have reported “harrowing levels of death, injury and destruction” in northern Gaza.

Health workers, meanwhile, warned of a catastrophic situation there as scarce supplies are quickly dwindling amid the continuing siege.

Hussam Abu Safia, the director of the Kamal Adwan Hospital in northern Gaza, said Israeli army tanks surrounded the facility and that the hospital was “directly targeted” on Thursday.

He told Al Jazeera Arabic tank shelling on the hospital caused severe damage to its intensive care unit. Israeli soldiers also opened fire towards the facility’s windows, Abu Safia said, as well as the hospital’s main entrance, causing widespread “fear and panic” among children and patients inside.

The previous day, he said more than 150 wounded individuals were inside the hospital, including 14 children in intensive care or the neonatal department.

“There is a very large number of wounded people, and we lose at least one person every hour because of the lack of medical supplies and medical staff,” Abu Safia said in a video message on Wednesday.

“Our ambulances can’t transfer wounded people,” he said. “Those who can arrive by themselves to the hospital receive care, but those who don’t just die in the streets.”

Footage shared with The Associated Press news agency shows medical staff tending to premature babies and several older children in hospital beds, some with severe burns. One child is seen attached to a breathing machine, with bandages on her face and flies hovering over her.

“We are providing the bare minimum to patients. Everyone is paying the price of what is happening now in northern Gaza,” Abu Safia said.

Kamal Adwan is one of three hospitals in the north left largely inaccessible because of the Israeli attacks. The war has gutted the health system across Gaza, with only 16 of 39 hospitals even partially functioning, according to the World Health Organization.

Gaza’s civil defence said they had suspended operations in the north, accusing Israeli forces of threatening to kill its crews.

Israeli forces fired on one of their teams in the town of Beit Lahiya after ordering them to relocate to the Indonesian Hospital, where troops are stationed.

Three civil defence members were wounded in the strike, and a firetruck was destroyed, the civil defence said in a statement. It said another five of its personnel were detained by Israeli forces at the hospital.

“As a result, we declare that Civil Defence operations in the northern Gaza Strip have been completely halted, leaving these areas without any firefighting, rescue, or emergency medical services,” it said.

Siege continues

Al Jazeera’s Hind Khoudary, reporting from central Gaza’s Deir el-Balah, said the situation for civilians in the north was “miserable”.

“No food, no water, no civil defence teams, no ambulances, no paramedics,” Khoudary said.

Israeli forces are “forcing people to leave their houses, to leave their shelters, and also separating families from one another,” she said. “They’re putting numbers on men. They’re putting numbers on people and interrogating them.”

Israel’s deadly assault on Gaza that began in October last year has destroyed much of the besieged enclave’s infrastructure and internally displaced approximately 90 percent of Gaza’s population of 2.3 million, often multiple times.

Hundreds of thousands of people are crammed into tent camps along the coast after entire neighbourhoods in many areas were pounded to rubble.

More than 42,000 people have been killed, according to Palestinian health authorities, while thousands of others are either missing or trapped under the rubble.

The United States and Qatar announced on Thursday that negotiations on a Gaza ceasefire were set to resume.

Months of ceasefire negotiations brokered by Qatar, the US, and Egypt sputtered to a halt during the middle of the year.

US Secretary of State Antony Blinken met Qatari officials in Doha on Thursday and said ceasefire talks would resume “in the coming days”.