"Myanmar's military has conceded its troops abused prisoners in Rakhine state after a video of soldiers battering blindfolded detainees spread on social media - a rare admission of wrongdoing by a force often accused of acting with impunity. The video, which emerged on Sunday, shows plain-clothed men punching and kicking the heads of handcuffed and blindfolded detainees. More: UN envoy calls for investigation into "possible war crimes" in Myanmar as Rakhine conflict continues Eight killed in Myanmar's troubled western state of Rakhine Myanmar to release 25,000 prisoners to mark New Year festival The five detainees had been arrested on suspicion of being Arakan Army (AA) fighters and were being transferred to Rakhine state capital Sittwe by boat on April 21 when the incident occurred, according to the army chief's office website. Myanmar's armed forces are locked in an increasingly brutal war with the rebels, who are fighting for more autonomy for ethnic Rakhine Buddhists. UN's outgoing human rights envoy to Myanmar slams Suu Kyi (05:27) Some security force members interrogated the prisoners in a way "not in accordance with the law" and action would be taken against those responsible, the statement said, without giving details on what punishments await..."