The gunman, a 59-year-old staff worker at the Royal Thai Army War College, shot at his colleagues at around 8.55 a.m., Xinhua news agency quoted deputy army spokesperson Sirichan Ngathong as saying.
The perpetrator was taken into custody after he surrendered to the police and the motive for the shooting is still unclear, he said.
According to the spokesperson, the injured person is hospitalised and the army will set up a special team to investigate the incident.
In the past year, there have been at least two other cases of shooting murders by serving soldiers, according to the Bangkok Post.
In 2020, in one of the country’s deadliest incidents in recent years, a soldier gunned down 29 people in a 17-hour rampage and wounded scores more before he was shot dead by commandos.