The tragedy reportedly occurred about 7.30am at the Air Support Command headquarters of the Border Patrol Police in Naresuan camp in Prachuap Khiri Khan province.
Eight second-year cadets of Class 69 of the Police Academy and an instructor jumped from the plane as a team. The parachutes of the instructor, Pol Col Preecha Boonsuk, and two cadets opened normally and they landed safely.
But the parachutes of six cadets did not open. Four of them managed to open their reserve parachutes and landed safely, but the other two plummeted to the ground.
The two who died were identified as police cadets Chayakorn Puthachaiyong and Nathawuth Tirasuwansuk. (correcting names in earlier report)
The reports said their static lines failed to deploy the parachutes. It was believed the line they were attached to broke.