At 7:41:18 p.m. Thursday, a 3.9 magnitude earthquake occurred 7 kilometers northeast of Yongrim in Jagang Province, North Korea, according to the Korea Meteorological Administration. (Yonhap)

A 3.9 magnitude earthquake struck North Korea's northwestern province bordering China on Thursday, which is believed to be a natural one, the South Korean weather agency said.

The quake struck an area 7 kilometers northeast-east of Ryongrim in Jagang Province, at 7:41 p.m., according to the Korea Meteorological Administration.

The epicenter was at a latitude of 40.54 degrees north and a longitude of 126.75 degrees east, the KMA said.

The quake is believed to have occurred naturally, it added.