Two earthquakes that jolted South Korea on Monday night, including the largest ever recorded in the country, prompted concerns about the safety of nuclear plants clustered in the quake-prone southeast.

Korea's Meteorological Agency said the two earthquakes, of magnitude of 5.1 and 5.8, occurred near the city of Gyeongju. They could be felt in the capital Seoul, over 300 km to the northwest.

Fourteen people were injured but there were no reports of serious damage, a Ministry of Public Safety and Security official said.