The Israeli military announced Saturday night that it had killed Mohammed Sinwar, one of Hamas’ top military commanders in the Gaza Strip, during airstrikes in May that targeted the vicinity of a hospital in southern Gaza.

Hamas did not immediately respond to the claim of Sinwar’s death. During the war, the Palestinian armed group has largely not confirmed the killing of its commanders in the moment, only announcing their demise weeks or even months later, if at all.

Sinwar’s death would leave the hierarchy of Hamas’ leadership in Gaza unclear. Another senior Hamas militant, Izz al-Din al-Haddad, is believed to command the group’s remaining fighters in northern Gaza.

Israeli Defense Minister Israel Katz threatened al-Haddad on Saturday night as well as Khalil al-Hayya, one of Hamas’ leaders in exile, saying they would share a similar fate as Sinwar.

“You are next in line,” Katz said in a statement, addressing the two militant leaders by name.

But Sinwar’s death may not immediately change Hamas’ strategy or operations, analysts said. Since the war began more than a year and a half ago, Israel has targeted and killed a number of Hamas’ top leaders, only to see the group continue its guerrilla war against Israel in Gaza.

In May, Israeli aircraft struck an underground compound near the European Hospital, close to the southern Gaza city of Khan Younis, where Sinwar had recently been present, according to the Israeli military. At the time, Israeli officials said privately that they had been targeting Sinwar, but they did not mention him in their announcement of the strikes. The Gaza Health Ministry said that at least six people had been killed and at least 40 others wounded in that strike.