Mustafa Muhammad Abu Ara, a Hamas leader from the West Bank, died in Israeli custody on Friday, according to Palestinian authorities and the militant group. Abu Ara, 63, passed away after being transferred from a southern Israeli prison to a hospital, as confirmed by a joint statement from the Palestinian Authority’s prisoners affairs body and the Palestinian Prisoners’ Club watchdog.

Hamas has condemned his death, accusing Israel of “assassination through deliberate medical neglect.” They claim that Abu Ara, who was arrested in October, endured severe health issues, torture, and starvation during his detention.

The Israeli military has not yet responded to requests for comment. Palestinian officials have recently accused Israel of conducting an abusive “war of revenge” against Palestinian detainees since the onset of the Israel-Hamas conflict. Israel, however, has denied these allegations, asserting that it operates within international law.