A gyro sensor error is believed to have caused a Hyunmoo-2C missile to crash during South Korea's own launch conducted in response to the North’s ballistic missile firing back in October.

The defense ministry said on Friday that it made the presumption based on a two-month investigation of the crash until the end of November.

The team ran some 30-thousand flight simulations and deduced that an error with the gyroscopic sensor led the Hyunmoo-2C missile to crash in the eastern Gangneung region on October 4.

Also known as “angular rate sensors” or “angular velocity sensors,” gyro sensors measure and maintain the orientation and angular velocity of a missile.

The ministry said it found no errors in the process of electrifying the Hyunmoo-2C missile or in the process of launching it.

To prevent the recurrence of similar incidents, the ministry will inspect all Hyunmoo-2C missiles and other missiles produced around the same time through next March.