North Korea fired several short-range ballistic missiles toward the Sea of Japan on Friday, the Joint Chiefs of Staff of the South Korean military said, reports Yonhap News Agency. The Joint Chiefs of Staff did not provide further details on flight range and other capabilities as an analysis is currently underway. According to the South Korean side, the launch comes after the North fired 600-mm super-large shells, considered to be short-range ballistic missiles, toward the Sea of Japan on April 22. North Korean state media said leader Kim Jong-un has guided tactical drills simulating a nuclear counterattack involving "super-large" multiple rocket launchers for the first time.