SEOUL, Feb. 11 (Xinhua) -- An earthquake of 4.6 magnitude struck an area in southeast South Korea, with no serious casualty being reported yet, the weather service said Sunday.

The 4.6-magnitude tremor hit an area, 5 km northwest of the northern district in the country's southeastern coastal city of Pohang in North Gyeongsang province at about 5:03 a.m. local time (2003 GMT Saturday), according to the Korea Meteorological Administration.

The epicenter, with a depth of 14 km, was at 36.08 degrees north latitude and 129.33 degrees east longitude.

The weather agency believed that it was an aftershock of the country's second-strongest quake that hit the Pohang city on Nov. 15 last year. The seismic intensity of the Nov. 15 tremor was 5.4 magnitude.

No life-threatening injury was reported. According to local media reports, 22 people sustained minor injuries.