The killings were overseen by a powerful gang leader convinced that his son’s illness was caused by followers of the religion, according to civil organization the Committee for Peace and Development (CPD). “He decided to cruelly punish all elderly people and voodoo practitioners who, in his imagination, would be capable of sending a bad spell on his son,” a statement from the Haiti-based group said.

UN rights commissioner Volker Turk said that at least 184 people were killed in the weekend violence.

Calling the bloody episode an “act of barbarity, of unbearable cruelty,” the office of Prime Minister Alix Didier Fils-Aime said his government “condemns in the strongest terms the abject massacre.” “This monstrous crime constitutes a direct attack on humanity and the republican order,” it added. Both the CPD and UN said that the massacre took place in the capital’s western coastal neighborhood of Cite Soleil.

“The gang’s soldiers were responsible for identifying victims in their homes to take them to the chief’s stronghold to be executed,” the CPD said.

Gangs now control 80 percent of the city. Despite a Kenyan-led police support mission, backed by the United States and UN, violence has continued to soar. Turk told reporters in Geneva that the latest killings “bring the death toll just this year in Haiti to a staggering 5,000 people.”

More than 700,000 people are internally displaced in Haiti, half of them children, according to October figures from the UN’s International Organization for Migration.

Voodoo was brought to Haiti by African slaves and is a mainstay of the country’s culture. It was banned during French colonial rule and only recognized as an official religion by the Haitian government in 2003. While it incorporates elements of other religious beliefs, including Catholicism, voodoo has been historically attacked by other religions.