Seoul - South Korea detected an "artificial earthquake," which may be an indication that Pyongyang went ahead with its threat to conduct another nuclear test, South Korean media said Monday.

"It was felt shortly before 10 am (0100 GMT)," a source, who declined to be named, was quoted as saying by the South Korean Yonhap news agency. The magnitude was estimated at 4.5 on the Richter scale. (dpa)