Omer Neutra, who had Israeli and U.S. dual citizenship, was doing military service in Israel when Hamas invaded. His parents have been high-profile campaigners for the hostages.

Hamas said on Monday that 33 hostages in Gaza had been killed during the almost 14-month-old war between the Palestinian militant group and Israel in the enclave, without giving their nationalities.

Israel’s Foreign Minister Israel Katz said in a statement that Neutra “fell in a heroic battle near Nir Oz on October 7.” Nir Oz, a small kibbutz near Gaza in southern Israel, was one of the communities worst impacted by the terror attacks of October 7, with one in four residents murdered or kidnapped.