Chinese fishing boats have recently abandoned the waters off the western coast lying between the two Koreas.

A military official said Wednesday that no Chinese fishing vessels have been spotted this month in waters near the Northern Limit Line, but that North Korean fishing boats continue to operate in the waters as usual.

The official said it was not clear why the Chinese boats had withdrawn from the waters but suggested that the move could be nothing more than the result of a fishing accord between Pyongyang and Beijing.

The official said no peculiar movements by the North’s military have been detected, adding that the South is on heightened alert for any unusual signs that the communist state might be looking to make a strategic move.