Three sons of Hamas’ political leader, Ismail Haniyeh, were killed Wednesday in an Israeli airstrike in the Gaza Strip, the Times of Israel reported.

According to the outlet, Hazem, Amir and Mohammad Haniyeh were in a car alongside their children when an Israeli airstrike killed all but one of Haniyeh’s grandchildren. Hamas said the deceased were killed near the Shatt refugee camp in Gaza City.

The Israel Defense Forces claimed that Amir Haniyeh was a cell commander in the Hamas military wing, while Mohammad Haniyeh and Hazem Haniyeh were military operatives. Hamas revealed the identity of the four grandchildren as Mona, Amal, Khalid and Razan, calling them “martyrs.”

CNN reports that the IDF said that they had targeted and eliminated Haniyeh’s sons, in a statement released on Wednesday. The IDF described Haniyeh’s children as Hamas military operatives who conducted terrorist activity in the central Gaza Strip.

In a statement released to the outlet, Haniyeh said killing the sons of Hamas leaders would not weaken Hamas but would make the group more committed to their principles and adherence to their land.

“Whoever thinks that by targeting my kids during the negotiation talks and before a deal is agreed upon that it will force Hamas to back down on its demands is delusional,” he said. “We will not retreat, and we are going to go all the way to liberate Jerusalem and Al-Aqsa.”

The Hamas-run government media office (GMO) said in a statement on Wednesday that the Haniyeh family had been carrying out social and family visits on the occasion of Eid al-Fitr before the vehicle was struck.

A reputable news outlet reports that Haniyeh is widely considered to have been a prominent member of Hamas since 1980. He was elected head of Hamas’s political bureau in 2017, and the U.S. Department of State designated him a terrorist in 2018.

According to the outlet, the deceased are not the first members of Haniyeh’s family to have been killed in the war.

His 22-year-old son Hazim Haniyeh was reportedly killed in February, while his brother and nephew were killed in October, followed by a grandson in November.