Omer Wenkert, 22, a restaurant manager from Israel, was among the crowd at the Tribe of Nova festival in Re im when Hamas gunmen stormed the site and opened fire, killing at least 260 people.
Hamas gunmen have kidnapped Israeli grandmothers and have taken them into the Gaza Strip on golf carts and motorcycles, amid reports that they have snatched more than 50 civilians.
Palestinian Islamist group Hamas took Israel by surprise with the biggest attack in decades as gunmen killed scores of people and brought hostages back into the Gaza Strip.