At least 50 people have been killed in Israeli air strikes across Gaza, Palestinian medics say, as Israeli tanks push into northern parts of the Khan Younis area in southern Gaza.

Medics said at least 20 people were killed and others wounded in an Israeli attack on Wednesday on a tent encampment in al-Mawasi near Khan Younis. The Palestinian Civil Defence said the attack set several tents housing displaced families ablaze.

Al Jazeera’s Hani Mahmoud, reporting from Deir el-Balah in central Gaza, said the death toll was expected to rise.

Patients who are in the hospital were “expected to lose their lives simply because there is no medical care, medical supplies and insufficient medical staff,” Mahmoud said.

“This is not the first time we’ve seen this happening. There’s a growing frustration among the displaced population in the al-Mawasi evacuation zone,” he said. “The Israeli military ordered them in the initial weeks of this genocidal war to evacuate in order to avoid being bombed, but they repeatedly find themselves the victims of these unpredictable attacks.”

At least 10 people were killed in an Israeli air strike that hit three houses in Gaza City, the Civil Defence said. Many victims were still trapped under the rubble with rescue operations under way.

Medics said 11 people were killed in three air strikes on areas in central Gaza, including six children and a medic. Five of the dead had been queueing outside a bakery, they said.

A further nine Palestinians were killed by tank fire in Rafah near the border with Egypt, medics said.

‘Extremely urgent’

Israeli forces also fired on Kamal Adwan Hospital in Beit Lahiya in northern Gaza for the fifth straight day, hospital Director Hussam Abu Safiya said. Three of his medical staff had been wounded, one critically, on Tuesday night, he said.

“Drones are dropping bombs filled with shrapnel that injure anyone that dares to move,” Abu Safiya said. “This situation is extremely urgent.”

He said more than 100 patients inside the besieged hospital are at risk of death and Israeli forces are preventing access to the nearby al-Awda Hospital.

Residents in the north’s main three towns – Jabalia, Beit Lahiya and Beit Hanoon – said Israeli forces have blown up dozens of houses.

Palestinians said Israel’s army is trying to drive people out of the northern edge of Gaza by issuing threats that if residents do not flee, they risk death and by carrying out bombardments to create a buffer zone. The Israeli military has besieged the area since it began a renewed ground offensive there nearly two months ago.

The siege has worsened an already dire humanitarian crisis amid a looming famine.

Hamas said the bombings of homes in Beit Lahiya and the targeting of Kamal Adwan Hospital are “an insistence on the ongoing war” and “genocide” in Gaza.

The group said in a statement that Israel is showing it plans to keep disregarding international law “in light of the shameful failure of the international system to put an end to these horrific crimes”.

Hamas said Israeli actions “are carried out under the full cover and protection of the American administration and some Western capitals”.

In the Khan Younis area, residents told the Reuters news agency that Israeli tanks advanced a day after the military issued new evacuation threats, saying there had been rocket launches by Palestinian groups from the area.

With shells crashing near residential areas, families left their homes on Wednesday and headed westwards towards al-Mawasi, which was designated by the Israeli military as a “safe zone” but has since repeatedly come under attack.

Palestinian and United Nations officials said there are no safe areas left in Gaza and almost all of its 2.3 million residents have been displaced multiple times.

Israel’s military campaign has killed more than 44,500 Palestinians, injured many others and reduced much of the enclave to rubble since it began in October last year.

Israel agreed to a ceasefire with the Lebanese armed group Hezbollah last week that has halted most fighting in a conflict that has unfolded in Lebanon in parallel with the Gaza war.

But the war in Gaza has ground on with only a single ceasefire more than a year ago that lasted for one week.