The United Nations and Palestinian factions from across the political spectrum reacted with outrage after Palestinian security officers arrested a Palestinian man and beat him to death in prison on Tuesday morning. The UN denounced the killing as an “apparent extrajudicial execution.”

Ahmad Izz Halaweh, the main suspect in a shooting by several gunmen onThursday which left two Palestinian policemen dead, was arrested during predawn raids in the Old City of Nablus in the northern occupied West Bank. He was taken to the Juneid security compound, where he was attacked and severely beaten by security officers.

The Governor of Nablus, Akram Rujoub, later pronounced him dead

A graphic photo shared on social media of Halaweh after the brutal attack showed his face, neck, and shoulders severely bruised and swollen.

Halaweh, reportedly the most prominent Nablus-area leader of Fatah’s military wing, the Al-Aqsa Martyrs Brigade, was the third civilian to be killed by Palestinian security officers, following Thursday’s shooting.

Shortly after Halaweh’s killing, Palestinian Prime Minister, Rami Hamdallah, announced that a special committee would be formed to look into Halaweh’s death and publicly share the results of the investigation, calling the situation “exceptional.

Hamas spokesperson, Sami Abu Zuhri, released a statement on Hamas’ Arabic website calling the act “a dangerous development of a policy of field executions by PA security services.”

“Such crimes reflect the bloody nature of the PA’s security coordination with the Israeli occupation,” Zuhri added, which he said has escalated into “a policy of oppression against our own people.”

Munir al-Jaghoub, head of media for the Fatah movement, responded by saying in a statement that Hamas used media to “mislead the Palestinian people and to promote breaking the law.”

Al-Jaghoub argued that Hamas “distorted facts about the application of the law by Palestinian security forces” who are committed to “fighting all corruption that threatens the safety of Palestinian people.”