The air strikes have killed 1,417 Palestinians, according to the Gaza Health Ministry on Thursday, with 6,268 wounded.

Officials have not said how many civilians are among the dead, but aid workers warn that Israel’s decision to impose a “complete siege” on the crowded enclave of 2.3 million people is spawning a humanitarian catastrophe that touches nearly every one of them.

The air strikes have transformed lively neighbourhoods into wastelands of rubble strewn with bodies. There is no clean water. And there is darkness – the territory’s only power plant ran out of fuel Wednesday, leaving only generators that will not last long.

“This is an unprecedented scope of destruction,” said Miriam Marmur, a spokeswoman for Gisha, an Israeli human rights group. “Israeli decisions to cut electricity, fuel, food and medicine supplies severely compound the risks to Palestinians and threaten to greatly increase the toll in human life.”

The Israeli bombardment has escalated in retaliation for Hamas militants’ unprecedented multifront attack Saturday. The Israeli military says more than 1,200 were killed and dozens more abducted, and the government declared war, promising a punishing campaign to destroy Hamas’ military capabilities. State broadcaster Kan put the Israeli death toll at 1,300 on Thursday.

Palestinians say Israel has largely unleashed its fury on civilians – a population that has lived for 16 years under a crippling blockade imposed by Israel and through four devastating wars and other hostilities.

The strikes across Gaza, from its farming villages on the northern border to upmarket towers in the heart of Gaza City, have killed 171 women and at least 326 people under 18, the Gaza Health Ministry said.

Eight journalists have been killed, local media organisations said, and six medics, according to the Palestinian Red Crescent. The UN agency for Palestinian refugees reports 11 of its staffers among the dead.

During past wars, news of a single shattered neighbourhood could shake the international community. This time, Israeli air strikes are rapidly laying waste to vast swathes of Gaza, and casualties are mounting too fast for anyone to keep up.

“In previous escalations, there would always be some time, even a half-hour, without air strikes,” said Nebal Farsakh, spokesperson for the Palestinian Red Crescent. “But now, there is not a single minute. That’s why the casualties keep going up and up.”

The stark toll is palpable at Gaza hospitals.

Even in ordinary times, they’re poorly supplied. Now, there’s a shortage of everything from bandages to intravenous fluids, beds to essential drugs, said Richard Brennan, regional director of the World Health Organization.

“It’s almost as bad as it gets,” Brennan said. “It’s not just the damage, the destruction. It’s that psychological pressure. The constant shelling … the loss of one’s colleagues.”

An air strike hit one of the territory’s biggest hospitals, in northern Beit Hanoun, rendering it inoperable. Shrapnel has flown into seven other hospitals and 10 UN emergency shelters, according to the World Health Organization and United Nations.

At Shifa Hospital, doctors battled to keep the place running. Fuel supplies ran low, and panic ensued outside. As explosions crashed, women and children streamed into the streets with their belongings, some of them barefoot.

From the hospital corridor, Muhammad Al-Gharabli recalled four missiles crashing into a mosque in the seaside Shati refugee camp Monday, decapitating his two-year-old son, Mohammed, and sending shrapnel into the leg of his two-year-old son, Lotfi.

Al-Gharabli said that when he regained consciousness, he saw the bodies of dozens of neighbours strewn over the ruins of their homes. He recognised the still and bloodied face of his next-door neighbour, a car mechanic.

“I can’t sleep from the horror,” he said.

In many cases, residents say, the Israeli military has bombed residential towers without the usual warning shots, wiping out families in their homes. Israel says it is going after only militant targets and does its utmost to avoid civilian casualties – a claim the Palestinians reject.

The Gaza Health Ministry has reported 22 incidents in which air strikes have killed many members of the same extended family, without providing details. The Israeli military rarely comments on individual air strikes.

For the densely populated Bureij refugee camp in central Gaza, the mayhem began early Wednesday. Jaber Weshah said there was no warning when a strike pummelled the multistorey building next door.

Few survived. Some people remained trapped under the rubble, awaiting ambulances for hours, Weshah said.

The death toll from that strike reached 12, residents said. Among the dead was a bookseller, his wife and two toddler daughters; a landlord, his son and his disabled sister; and six members of one family, leaving only its patriarch.

“It was an inferno,” said Weshah, a 73-year-old human rights activist. “If you’re trying to confront Hamas, I get it, you can do that. But you have the best military technology and you can’t differentiate between who is a civilian and who is not?”

When Israeli air strikes pounded Jabalia refugee camp in northern Gaza, at least 50 people – including two entire families – were killed and much of the camp razed, health authorities and residents said. The Israeli miliary said that the targets it struck “were only directed at Hamas situation rooms and operational apartments”.

One of the families killed were the Masouds – two public schoolteachers and their sons, ages 12 and 10 – according to neighbour Khalil Abu Yahia.

“They would sacrifice their lives to care for their children,” he said of parents Alaa and Atallah.

The morning of the strike, the family of four huddled close in the one room, far from the windows.

Abu Yahia knows this, he said, because that is how all four bodies were found.