The South Korean military has reported that three apparent explosions were heard just north of the border that separates the two Koreas, as well as in an area where North Korean troops are stationed.

It is not immediately clear what caused the noises. Speaking on condition of anonymity a South Korean military official said they might have been "just normal explosions,'' required for regular mining operations or construction. Another anonymous military source mentioned local army drills as the possible cause. 

Tensions have been high in the region since North Korea conducted a nuclear test on October 9th.