A 2.9 magnitude earthquake has been recorded near Kim Jong-un's nuclear test site.
It comes after a 6.1-magnitude magnitude quake last month, which Pyongyang claims was the result of hydrogen bomb test.
Today's quake was 23km north east of Sungjibaegam, towards the border with China, which has been used by the secret state to carry out nuclear drills.
A statement on the US Geological Survey website reads: "This event occurred in the area of the previous North Korean Nuclear tests.
"The event has earthquake like characteristics, however, we cannot conclusively confirm at this time the nature (natural or human-made) of the event."
A 3.4 magnitude quake last month near the same location sparked fears there could have been another nuclear test.