An airstrike from Israel killed three sons of Hamas’ top political leader in the Gaza Strip on Wednesday, striking high-stakes targets at a time when Israel is holding delicate cease-fire negotiations with the militant group. Hamas said four of the leader’s grandchildren were also killed.

Ismail Haniyeh ’s sons are among the highest-profile figures to be killed in the war so far. Israel said they were Hamas operatives, and Haniyeh accused Israel of acting in “the spirit of revenge and murder.”

The slayings also come as Israel is under intensifying pressure — increasingly from its top ally, the U.S. — to change tack in the war, especially when it comes to humanitarian aid for desperate people in Gaza.

Haniyeh said Hamas would not cave to the pressure leveled by the strike on his family.

“The enemy believes that by targeting the families of the leaders, it will push them to give up the demands of our people,” Haniyeh told the Al Jazeera satellite channel. “Anyone who believes that targeting my sons will push Hamas to change its position is delusional.”

Hamas’ Al-Aqsa TV station aired footage of Haniyeh receiving the news of the deaths through the phone of an aide while visiting wounded Palestinians who have been transported to a hospital in Qatar, where he lives in exile. Haniyeh nodded, looked down at the ground and slowly walked out of the room.

Hamas said Hazem, Amir and Mohammed Haniyeh were killed in the Shati refugee camp in Gaza City, where Ismail Haniyeh is originally from. The militant group said three of Haniyeh’s granddaughters and a grandson were also killed, without disclosing their ages.

Al-Aqsa TV said the brothers were traveling with family members in a single vehicle targeted by an Israeli drone.

The Israeli military said Mohammed and Hazem were Hamas military operatives and that Amir was a cell commander. It said they had conducted militant activity in the central Gaza Strip, without elaborating. It did not comment about the grandchildren killed.

The strike on Haniyeh’s family is the latest bloodshed in a war with no end in sight.

Earlier, Israeli War Cabinet minister Benny Gantz claimed Hamas has been defeated militarily, although he also said Israel will fight it for years to come.

“From a military point of view, Hamas is defeated. Its fighters are eliminated or in hiding” and its capabilities “crippled,” Gantz said in a statement to the media in the southern Israeli city of Sderot.

But he added: “Fighting against Hamas will take time. Boys who are now in middle school will still fight in the Gaza Strip.”

Gantz reiterated the Israeli government’s commitment to go into Rafah, the city at the far southern tip of the Gaza Strip where more than half the territory’s 2.3 million people are now sheltering.

For Palestinians, the strike on Haniyeh’s family darkened an already grim Eid al-Fitr holiday, which ends the holy fasting month of Ramadan. Palestinians marked the holiday by visiting the graves of loved ones killed in the war. In the Jabaliya refugee camp near Gaza City, people sat quietly by graves surrounded by buildings destroyed in Israel’s offensive, which was launched in response to the deadly Hamas attack on Oct. 7.

Bd-pratidin English/Lutful Hoque