A magnitude 3.1 earthquake struck about 35 kilometers south of Pyongyang in North Hwanghae Province, the Korea Meteorological Administration said on Monday.

South Korea’s weather agency has quickly denied the possibility that the earthquake was man-made, and confirmed that it was a natural earthquake.

“The earthquake observed on 5:17 a.m., March 14, 2016, about 21 kilometers east of Songrim city, North Korea, was a natural occurrence,” Lee Ji-min a researcher from the Earthquake and Volcano Monitoring Division of the Korea Meteorological Administration (KMA) told NK News.

The researcher said he could clearly read both the strong P wave and S wave, which are