SEOUL, Sept. 12 (Xinhua) -- An earthquake with a preliminary magnitude of 5.8 jolted southeastern South Korea, the biggest-ever striking the country, about an hour after a 5.1-magnitude tremor occurred, local media outlets reported on Monday, citing the country's weather agency.
The 5.1-magnitude tremor struck on the outskirts of Gyeongju city in North Gyeongsang province at 7:44 p.m. local time. The epicenter was located about 9 km southwest of the city.
The second tremor with a magnitude of 5.8 struck the nearby region, just 1.4 km away from the first epicenter, at 8:32 p.m. local time.
It was the country's biggest-ever quake, surpassing the previous strongest tremor that happened in January 1980.
The tremor was felt nationwide from adjacent cities of Ulsan and Busan to as far north as capital Seoul and far south as the southern resort island of Jeju.
There has been no damage reported yet, the Ministry of Public Safety and Security was quoted as saying.