North Korean leader Kim Jong Un reportedly issued the order to fire more than 100 rockets into the Sea of Japan on Monday.
The rockets were launched from a location on the country's east coast, just several hundred meters north of the Demilitarized Zone.
The Korean Workers' Party newspaper Rodong Sinmun said on Tuesday that Kim himself ordered launching rockets as he oversaw a live-shell firing drill by an eastern frontline military unit near the inter-Korean border.
The newspaper didn't say when the exercise took place. But its description of the location and a supplied photo showing what looks like rockets suggest that it refers to the firings on Monday.
North Korea launched 2 short-range ballistic missiles last Wednesday. The country's state media said the next day that Kim ordered the launch.
The reports of Kim guiding live-fire drills appear designed to counter a scheduled joint maritime exercise between the US and South Korean forces, as well as to raise the morale of North Korean soldiers.
Jul. 15, 2014 - Updated 03:27 UTC