South Korea's Army said Tuesday a mechanical flaw triggered the explosion of a K-9 Thunder self-propelled howitzer in August that left three soldiers dead and four others wounded.

The howitzer blew up abruptly while in use at a shooting range in Cheorwon, Gangwon Province. The Army has since suspended the operation of K9s for training purposes, although it remains operational for combat ones.

The detonator ignited by itself and some components functioned abnormally, the Army said after a joint investigation joined by 113 government, military officials and civilian experts.

This photo taken on Aug. 18, 2016, shows a K-9 self-propelled howitzers during an exercise in an army unit near the Demiliterized Zone. (Yonhap)
The announcement indicated no human error or mistake at the time of the accident.

In a press release, however, it did not directly mention the responsibility of the manufacturer of the artillery system, Hanwha Land Systems, an affiliate of Hanwha Techwin.

The Army plans to resume the use of K9s at training sites "in stages" and take additional safety measures for troops operating K9s, plus a better maintenance system. (Yonhap)