A Korean-made K-11 airburst assault rifle exploded during a demonstration live-fire session on Wednesday, leaving three soldiers with minor injuries.

The explosion came just three months after the military resumed its procurement of the rifle, which went through rigorous tests and readjustments following a rifle blast in October 2011.

“We planned to conduct three demonstration sessions. In the first and second sessions, we fired 60 shots and there was no problem. But the problem occurred during the third firing session,” an Army source said, declining to be named.

“The military authorities are now investigating what went wrong with the rifle.”

After the explosion in 2011, the military authorities and Defense Acquisition Program Administration conducted a slew of live-ammunition tests and nighttime operational tests to ensure the rifle’s safety.

With Wednesday’s blast, some critics have begun raising questions over the structural stability of what the military has touted as an “outstanding indigenous” rifle.

In 2011, the Defense Ministry formed a special panel to verify the cause of the explosion in that year. Experts at the time concluded that electromagnetic waves negatively impacted the rifle’s performance, which caused the rifle to malfunction.

Developed by the state-run Agency for Defense Development, the airburst rifle is designed for a variety of battle situations including dealing with enemy forces making stealthy infiltrations.

By Song Sang-ho (sshluck@heraldcorp.com)