Witnesses said that the Sunday shootout occurred around 6:00 a.m. local time near Rafah, near a site managed by the Gaza Humanitarian Foundation (GHF), supported by the United States and Israel, where people had gathered in the hope of receiving food.
The Israeli army said that it had pulled to warning suspects that approached troops in what it considers as an active combat zone.
The survivors described tanks and slaughtered people while they were fleeing.
It was the last in a series of shootings that killed more than 120 people and injured hundreds since the establishment of a new food distribution system, according to the Gaza Ministry of Health controlled by Hamas.
Critics say that the GHF system forces civilians to go to dangerous areas and do not meet urgent humanitarian needs.