Israeli airstrikes on Gaza overnight killed at least 104 Palestinians, including many children, in one of the deadliest attacks since the US-brokered ceasefire began. The assault has now become the biggest test for the fragile truce.

According to Gaza’s civil defence agency, at least 35 children were among the dead and more than 200 people were injured. The strikes came only hours after Donald Trump said that nothing would threaten the ceasefire agreement he helped broker.

Dr Mohammed al Mughir, director of humanitarian support and international cooperation at Gaza’s civil defence, told the Guardian, “Among these attacks was the targeting of a cancer patient camp, the Insan camp.”

Agence France-Presse confirmed the death toll after gathering reports from medical staff in five Gaza hospitals that received the victims.

Israeli Prime Minister Benjamin Netanyahu ordered the airstrikes on Tuesday evening following a clash between Palestinian militants and Israeli troops. His decision came amid growing anger in Israel after Hamas returned body parts of a hostage whose remains had been recovered by Israeli soldiers two years earlier.

Netanyahu called an emergency meeting to discuss what he called Hamas violations of the ceasefire, while far-right voices in his government pushed for a full return to war.

Hamas, which denied responsibility for the gun attack, postponed a planned handover of another hostage’s remains that was supposed to take place on Tuesday night after the airstrikes.

Speaking to reporters on Air Force One, Trump repeated that nothing would endanger the ceasefire but said Israel “should hit back” if its soldiers were killed. “They killed an Israeli soldier. So, the Israelis hit back. And they should hit back,” he said.

US Vice President JD Vance said earlier that the ceasefire was still holding despite “skirmishes.”

But the latest attack exposed how unstable the truce really was. Even before these strikes, Gaza’s media office had accused Israel of 80 ceasefire violations that killed 97 Palestinians and injured 230 others.

Mahmoud Bassal, the spokesperson for Gaza’s civil defence, described the situation as “catastrophic and terrifying,” calling the attacks “a clear and flagrant violation of the ceasefire agreement.” He told AFP, “The Israeli strikes targeted tents for displaced people, homes and the vicinity of a hospital in the strip.”

When asked whether the strikes marked a return to a full invasion, an Israeli Defence Forces spokesperson said on Tuesday that the military “can’t elaborate on the scale yet.” By Wednesday, the IDF announced that the Gaza ceasefire had been reinstated.

The Israeli military also released footage it said showed Hamas members reburying a body to “stage a false discovery” for the International Committee of the Red Cross. It accused Hamas of “attempting to create a false impression of efforts to locate the bodies.” Hamas has not commented on these claims.

The news has stirred outrage in Israel. Far-right ministers Itamar Ben Gvir and Bezalel Smotrich lashed out at Hamas and urged Netanyahu to resume the war immediately.

Under the ceasefire agreement, which took effect on 10 October, Hamas must return the remains of all Israeli hostages as quickly as possible. In return, Israel agreed to hand over 15 Palestinian bodies for every Israeli one.

So far, Hamas has returned 15 hostages’ remains, while 13 bodies still remain in Gaza. The group has claimed it no longer knows where all the bodies are because several of its units holding captives were killed in Israeli airstrikes.

Trump has admitted that some of the bodies may be hard to recover, but said, “others they can return now, and for some reason they are not.” He added, “It may have to do with the disarming of Hamas.”

Israel has made Hamas’s disarmament one of its main goals, calling it a crucial condition to end the two-year war.

On Sunday, Hamas’s chief negotiator Khalil al Hayya said the group’s weapons were “tied to the existence of occupation and aggression.” He added, “If the occupation ends, these weapons will be handed over to the state.” It is still unclear if he was referring to the new Palestinian governing authority expected to take over Gaza once Hamas gives up control.