Israel was checking on Monday if Hamas’s second-highest military leader died in an air strike, media said, as talks stumbled to secure a ceasefire in the Gaza war to coincide with the Muslim holy month of Ramadan.

If his death is confirmed, Marwan Issa would be the highest-ranking official from the Islamist terrorist movement taken out by Israel in the more than five-month war that has pulverized the Palestinian enclave and killed thousands.

Israeli Army Radio said Israel had bombed the Al-Nusseirat camp in central Gaza on Saturday night, where it had intelligence about the location of Issa, second-in-command of Hamas’s military wing the Izz el-Deen al-Qassam Brigades.

The attack killed five people, the report said.