The death sentence was carried out on Thursday by Hamas, the terror organization that controls the coastal strip.

The men were accused of being involved in giving information to Israeli military intelligence to aid in the assassination of top Hamas commander Mazen Fuqaha late last month in Gaza, which Hamas blames on Israel. Israel has neither affirmed nor denied involvement in the killing.

The men, ages 32, 42 and 55, were charged with providing information on the location of Hamas operatives and military sites over the past three decades. Hamas said they were allowed to defend themselves as provided under Sharia law.

The Palestinian Authority condemned the executions, said it was illegal since Hamas did not get the permission to execute from Palestinian Authority President Mahmoud Abbas.

Human Rights Watch also condemned the hangings, saying in a statement from Sarah Leah Whitson, executive director of the Middle East division of Human Rights Watch, that: “The abhorrent executions by Hamas authorities of three men in Gaza deemed to be collaborators project weakness, not strength. Hamas authorities will never achieve true security or stability through firing squads or by the gallows, but rather through respect for international norms and the rule of law.”