Hamas chief Ismail Haniyeh said the Palestinian group will not budge from its position on deadlocked ceasefire negotiations after Israeli forces killed three of his children and four of his grandchildren in northern Gaza on Wednesday.

Haniyeh, who is based in Qatar, confirmed the deaths of his sons Hazem, Amir, and Mohammed, who he said had been visiting relatives for Eid al-Fitr, the celebration of the end of Ramadan, at Shati refugee camp when they were targeted. Hamas also said in a statement that four of Haniyeh’s grandchildren—Mona, Amal, Khaled, and Razan, of undisclosed ages—were killed along with their parents in the holiday attack, which the Gaza Government Media office called “a massacre.”.

“All our people and all the families of Gaza residents paid a heavy price from the blood of their children, and I am one of them,” Haniyeh said in reaction to the news in a statement published by Hamas.

In a statement, the Israeli military confirmed targeting and killing Haniyeh’s three sons, described as “Hamas military operatives that conducted terrorist activity.” The statement did not mention Haniyeh’s grandchildren, who join the reported 600 children killed in the war in Gaza. Haniyeh’s family members were among over 120 people killed in Gaza on Wednesday, according to the Hamas-run Gaza health ministry, which says that “over 1,000 Palestinians have been killed in Gaza in the six months since the outbreak of the conflict.

Haniyeh, the chair of Hamas’ political bureau, said that around 60 of his family members have been killed. After the latest loss, he received condolences from Middle Eastern leaders, including the President of Turkey and Prime Minister of Qatar.

In recent weeks, Hamas and Israel have been engaging in indirect ceasefire negotiations, facilitated by international mediators, though the talks have reportedly stalled.

Israel is calling for the return of all hostages in exchange for a temporary ceasefire, while Hamas is demanding for a permanent end to hostilities, the full withdrawal of Israeli forces from Gaza, the return of displaced Gazans to their homes in the north, and the facilitation of humanitarian aid and reconstruction of the decimated enclave. Meanwhile, Israel maintains that it will not end the war or withdraw from Gaza until Hamas is no longer a threat. Each side has rejected the other’s demands.

The recent deaths of his family members have not altered Hamas’ stance, Haniyeh insisted on Wednesday.

“If they think that targeting my children at the peak of these talks before the movement’s response is submitted will cause Hamas to change its positions, they are delusional,” Haniyeh told reporters on Wednesday. “The blood of my children is not more valuable than the blood of the children of the Palestinian people.”

The U.S. has expressed frustration at the seeming indiscriminateness of Israel’s military campaign in Gaza, especially after several attacks on civilian targets. President Joe Biden has changed his tone on ceasefire negotiations, urging Israel rather than just Hamas to immediately accept a temporary ceasefire deal. “What I’m calling for is for the Israelis to just call for a ceasefire—allow for the next six, eight weeks, total access to all food and medicine going into the country,” Biden said. Nevertheless, Biden has maintained that U.S. support for Israel remains “ironclad.”