The air force is investigating the actions of three sergeants after a private was severely assaulted for using his smartphone outside approved hours.
Air force spokesman AM Pongsak Semachai said on Tuesday that air force chief ACM Chaiyapruk Didyasarin had ordered a fact-finding investigation into the reported punishment inflicted by three sergeants at an air force unit in Don Muang.
If the details of the assault were confirmed, those responsible would be disciplined.
The spokesman said photos of the private's injuries showed he was overly punished on July 2.
The private, 21, and his family filed a complaint with the Crime Suppression Division on Tuesday, accusing three air force sergeants of physical assault.
The private said he had volunteered in joining the air force, and had been in training for two months at the Air Force Military Police Regiment in Don Muang district.
On the morning of Tuesday July 2 he secretly used his smartphone, even though he was allowed to do so only on Fridays. He was caught red-handed and punished six times throughout that day.
He was punched, kicked and beaten with a bamboo stick; a bayonet was pressed onto his shoulder; his head was forcefully pounded onto his plate. He fled the regiment late that night and stayed with a friend, without telling his parents, he said.
His parents posted notice of his disappearance online. He contacted his parents on Sunday.
His injuries, which included large bruises on his buttocks, were examined by a doctor, who said he would need a week's sick leave to recover.
No names have been released.