
Anupong said that the rounds were for shooting practices in the army.
"I already ordered an urgent investigation into the matter to find out how the attackers on Sondhi got the cartridges of the M-16 assault rifles from our army unit," he said.
However he said it would be very difficult to find out what army unit the cartridges came from despite the fact that he knew they were from the 9 th Infantry Division which is under jurisdiction of the First Army Region.
Earlier reports showed that three spent cartridges from an M-16 assault rifle found at the scene of the assassination attempt on Sondhi last week were produced and widely used by the Army.
The cartridges were engraved with the initials of the Royal Thai Army and the serial numbers showed they had been distributed to a unit in the First Army region, the source said.
Also, 5.56-mm cartridges could have been fired from an M-203 grenade launcher - a modified M-16 rifle installed with a 40mm grenade launching tube under its barrel.