At least 19 people were killed, including several children, as an Israeli airstrike targeted a school hosting war-displaced people in northern Gaza's Jabalia, local medics said Thursday.

Dozens were also injured in the strike, said Palestinian official Medhat Abbas, adding: "There is no water to extinguish the fire. There is nothing."

The strike hit the Abu Hussein school in Jabalia, an urban refugee camp in northern Gaza where Israel has been waging a major air and ground operation for more than a week.

Fares Abu Hamza, head of the ministry's emergency unit in northern Gaza, confirmed the toll and said dozens of people were wounded. He said the nearby Kamal Adwan Hospital was struggling to treat the casualties.

"Many women and children are in critical condition," he said.

The Israeli military, sticking to its usual rhetoric, claimed the strike targeted dozens of Hamas and Islamic Jihad members who had gathered at the school, without providing any evidence.

Earlier in the day, Israeli airstrikes killed another 11 Palestinians in Gaza City, according to medics.

Choking the north

Israeli forces Thursday also sent tanks into Jabalia, where Palestinians and United Nations officials expressed alarm over shortages of food and medicine.

Residents of Jabalia said Israeli forces blew up clusters of houses from air, by tank shells and by placing bombs in buildings before blowing them up remotely.

Gaza's civil emergency service said it evacuated several wounded people from a school sheltering displaced Palestinians that caught fire after being hit by Israeli tank shells.

Residents said Israeli forces had effectively isolated Beit Hanoun, Jabalia and Beit Lahia in the far north of the enclave from Gaza City, blocking movement except for those families with permission to heed evacuation orders and leave the three towns.

"We have written our death notes and we are not leaving Jabalia," one resident told Reuters via a chat app.

"The occupation (Israel) is punishing us for not leaving our houses in the early days of the war and we are not going now either. They are blowing up houses and roads, and are starving us but we die once and we don't lose our pride," the father of four said, refusing to give his name fearing Israeli reprisal.

On Wednesday, the Israeli military said it had killed more than 50 Palestinian resistance members over the past days in airstrikes and close-quarters combat as troops try to root out Hamas.

Northern Gaza, which had been home to well over half the territory's 2.3 million people, was bombed to rubble in the first phase of Israel's attack on the territory a year ago, after the Oct. 7 Hamas incursion of Israeli towns caused 1,200 deaths and captured 250 hostages.

After a year of Israel's genocidal war killed more than 42,200 Palestinians, hundreds of thousands of residents have come back to ruined northern areas.

Israel sent troops back earlier this month claiming resistance members were regrouping. Hamas denies operating among civilians.

The United States has told Israel that it must take steps to improve the humanitarian situation in northern Gaza in 30 days or face potential restrictions on military aid.

Israeli Prime Minister Benjamin Netanyahu convened an emergency meeting on Wednesday to discuss expanding humanitarian aid to Gaza, three officials who had attended the discussion said, with aid likely to increase soon.