Seoul: Small quake in North Korea likely due to mining blast South Korea's weather agency says a small earthquake detected in North Korea was likely caused by a mining operation

SEOUL, South Korea -- South Korea's weather agency says a small earthquake detected in North Korea was likely caused by a mining operation.

An official from the Korean Meteorological Administration said Friday that a magnitude 2.1 earthquake was detected in North Korea on Thursday at a region near the border with the South.

The official says the quake was artificial and likely caused by an intentional blast in a coal mine.

"Our map data shows the locations of mines across North Korea, and we also detected soundwaves, proving that this quake was caused by an explosion," he said. He didn't want to be named, citing office rules.

The area is distant from the northeastern region where the North tested six nuclear devices until 2017. The North last year unilaterally demolished tunnels at its nuclear testing ground as it initiated diplomacy with Washington and Seoul.

North Korea's weakest nuclear test, its first one, conducted in 2006, generated a magnitude 4.3 quake. The U.S. Geological Survey measured the North's sixth and most powerful nuclear test in September 2017 at magnitude 6.3. The North then claimed it detonated a thermonuclear weapon built for its long-range missiles targeting the U.S. mainland.