An Israeli airstrike on Wednesday night killed Azzam Al-Hayya, the son of Khalil Al-Hayya, a senior Hamas leader and chief negotiator involved in U.S.-mediated discussions over the future of Gaza, according to a senior Hamas official. Azzam Al-Hayya succumbed to his injuries on Thursday, Hasim Naim, a Hamas official, confirmed.

The strike occurred amid ongoing talks in Cairo between Hamas leaders and representatives aimed at maintaining a fragile truce with Israel. The attack marks a significant escalation amid efforts to uphold ceasefire agreements that both sides have sought to stabilize.

On the same day, Gaza health officials and the Interior Ministry reported that at least three police officers were killed, and several others, including one policeman, were wounded when an Israeli airstrike hit a police post in western Gaza City. Reuters reported that Israel has increased its military actions targeting Gaza’s police force, which Hamas uses to assert control over the territories it governs.

Khalil Al-Hayya has survived several assassination attempts by Israel over the years. In a separate attack last year in Doha aimed at Hamas leadership, another of his sons was killed while he himself escaped harm. Two other sons were killed during Israeli strikes in Gaza in 2008 and 2014.

Following the attack on Wednesday night and prior to the confirmation of his son’s death, Khalil Al-Hayya told Al Jazeera that Israel’s actions were intended to sabotage the mediation process surrounding U.S. President Donald Trump’s Gaza peace plan. He accused Israel of refusing to respect the ceasefire and undermining progress in the talks.

In Gaza, dozens of Palestinians gathered to honor Azzam Al-Hayya during his funeral procession. Special prayers were held, and family members paid tribute to the white-shrouded body. A sister of the late Azzam said in a mosque that the deaths of her brothers, including Hammam, Osama, and Hamza, would not deter Khalil Al-Hayya from his political principles and commitments.

This latest incident highlights the fragility of the ceasefire and the ongoing volatility in Gaza despite diplomatic efforts to reach a lasting resolution.