DEIR AL-BALAH, Gaza Strip: Israel launched a wave of airstrikes across the Gaza Strip early Tuesday, saying it was striking dozens of Hamas targets in its heaviest assault in the territory since a ceasefire took effect in January. Palestinian officials reported at least 200 deaths.

Prime Minister Benjamin Netanyahu said he ordered the strikes because of a lack of progress in talks to extend the ceasefire. Officials said the operation was open-ended and was expected to expand. The White House said it had been consulted and voiced support for Israel’s actions.

“Israel will, from now on, act against Hamas with increasing military strength,” Netanyahu’s office said.

The surprise attack shattered a period of relative calm during the Muslim holy month of Ramadan and raised the prospect of a full return to fighting in a 17-month war that has killed tens of thousands of Palestinians and caused widespread destruction across Gaza. It also raised questions about the fate of the roughly two dozen Israeli hostages held by Hamas who are believed to still be alive.

Hamas accused Netanyahu of upending the ceasefire agreement and exposing the hostages “to an unknown fate.” In a statement, it called on mediators to hold Israel “fully responsible for violating and overturning the agreement.”

In the southern city of Khan Younis, Associated Press reporters saw explosions and plumes of smoke. Ambulances brought wounded people to Nasser Hospital, where patients lay on the floor, some screaming. A young boy sat with a bandage around his head as a health worker checked for more injuries, a young girl cried as her bloody arm was bandaged.

Many Palestinians said they had expected a return to war when talks over the second phase of the ceasefire did not begin as scheduled in early February. Israel instead embraced an alternative proposal and cut off all shipments of food, fuel and other aid to the territory’s 2 million Palestinians to try to pressure Hamas to accept it.

“Nobody wants to fight,” Palestinian resident Nidal Alzaanin said by phone from Gaza City. “Everyone is still suffering from the previous months,” he said.

US backs Israel and blames Hamas

The White House sought to blame Hamas for the renewed fighting. National Security Council spokesman Brian Hughes said the militant group “could have released hostages to extend the ceasefire but instead chose refusal and war.”

US envoy Steve Witkoff, who has been leading mediation efforts along with Egypt and Qatar, had earlier warned that Hamas must release living hostages immediately “or pay a severe price.”

An Israeli official, speaking on condition of anonymity to discuss the unfolding operation, said Israel was striking Hamas’ military, leaders and infrastructure and planned to expand the operation beyond air attacks. The official accused Hamas of attempting to rebuild and plan new attacks. Hamas militants and security forces quickly returned to the streets in recent weeks after the ceasefire went into effect.

Israel’s defense minister, Israel Katz, said the “gates of hell will open in Gaza” if the hostages aren’t released. “We will not stop fighting until all of our hostages are home and we have achieved all of the war goals,” he said.

Explosions could be heard throughout Gaza. Khalil Degran, a spokesman for the Health Ministry based at the Al-Aqsa Martyrs Hospital in central Gaza, said at least 200 people had been killed. The territory’s civil defense agency said its crews were having a difficult time carrying out rescue efforts because various areas were being targeted simultaneously.

Talks on a second phase of the ceasefire had stalled

The strikes came two months after a ceasefire was reached to pause the war. Over six weeks, Hamas released 25 Israeli hostages and the bodies of eight more in exchange for nearly 2,000 Palestinian prisoners in a first phase of the ceasefire.

But since that ceasefire ended two weeks ago, the sides have not been able to agree on a way forward with a second phase aimed at releasing the 59 remaining hostages, 35 of whom are believed to be dead, and ending the war altogether.

Hamas has demanded an end to the war and full withdrawal of Israeli troops in exchange for the release of the remaining hostages. Israel says it will not end the war until it destroys Hamas’ governing and military capabilities and frees all hostages.

Netanyahu has repeatedly threatened to resume the war.

“This comes after Hamas repeatedly refused to release our hostages and rejected all offers it received from the US presidential envoy, Steve Witkoff, and from the mediators,” Netanyahu’s office said early Tuesday.

Taher Nunu, a Hamas official, criticized the Israeli attacks. “The international community faces a moral test: either it allows the return of the crimes committed by the occupation army or it enforces a commitment to ending the aggression and war against innocent people in Gaza,” he said.

Gaza already in a humanitarian crisis

The war erupted when Hamas-led militants stormed into southern Israel on Oct. 7, 2023, killing some 1,200 people, mostly civilians, and taking 251 hostages. Most have been released in ceasefires or other deals, with Israeli forces rescuing only eight and recovering dozens of bodies.

Israel responded with a military offensive that killed over 48,000 Palestinians, according to local health officials, and displaced an estimated 90 percent of Gaza’s population. The territory’s Health Ministry doesn’t differentiate between civilians and militants, but says over half of the dead have been women and children.

The ceasefire had brought some relief to Gaza and allowed hundreds of thousands of displaced Palestinians to resume to what remained of their homes.

A renewed Israeli ground offensive could also be especially deadly now that so many Palestinian civilians have returned home. Before the ceasefire, civilians were largely concentrated in tent camps meant to provide relative safety from the fighting.

The return to fighting could also worsen deep internal fissures inside Israel over the fate of the remaining hostages. Many of the hostages released by Hamas returned emaciated and malnourished, putting heavy pressure on the government to extend the ceasefire.

The released hostages have repeatedly implored the government to press ahead with the ceasefire to return all remaining hostages, and tens of thousands of Israelis have taken part in mass demonstrations calling for a ceasefire and return of all hostages.