The Indonesian army have confirmed allegations that members of its special forces were behind the revenge killings of four prisoners in a jail in central Java.

Nine members of the Special Forces Command, also known as Kopassus, confessed to forcing their way into the Cebangon prison and shooting dead four prisoners awaiting trial accused of murdering their superior officer, First Sgt. Heru Santosa.

“The attack that happened on March 23 was indeed carried out by members of the Indonesian Army, in this case members of Kopassus… which has left four people dead,” said Brigadier General Unggul Yudhoyono, who led a probe into the killings.

The officers came forward after the initial investigation began March 29 and admitted they were involved in the crime, Untung told The Jakarta Globe, adding that the officers were loyal to their spirit of the corps and the murder of their comrade angered them.

“The perpetrators are ready to take responsibility of their action and we will conduct a thorough investigation,” he said.

Rights groups hailed the army’s rare admission of guilt after being frequently accused of killing civilians, reports AFP.