Last month, a North Korean ship, overloaded with soldiers, capsized in waters off the country's southern border, killing about 90 people, according to a South Korean television channel.
Seoul-based Chosun TV, citing a South Korean intelligence assessment, said on Monday that the incident in early May led to "significant internal turmoil" among the ranks of the North Korean army.
"The Great Ship" was carrying more than 130 workers, all mobilized by the army, and sank in a river while transporting the party to build border fortifications in the eastern part of the country, the statement said.
The report links the consequences to the "recent provocations" by Pyongyang against Seoul, including noisy missile launches, sending balloons to carry garbage across the inter-Korean border and jamming GPS in the peninsula's western seas.
North Korea, while unlikely to disclose related accidents, has not reported any incidents matching the report's data. Her embassy in Beijing did not respond to multiple requests for comment.
South Korea's National Intelligence Service has not released such estimates in its intelligence reports on the North. Seoul's spy agency could not be reached for comment after hours.
Last month, Chosun TV, also citing government sources, reported that a large-scale North Korean cyber operation had hacked the private messages of senior defense officials in the South, including the Ministry of Defense and the Joint Chiefs of Staff . The breach was later confirmed by the country's police and military.
The order to mobilize 1,000 troops a day began in mid-January after North Korean leader Kim Jong Un's fiery national address in which he called the South a "main enemy" of his regime, a move that led longtime North Korea watchers to conclude that Kim had made up his mind to go to war.
North Korea's Defense Minister Kang Sun Nam visited the scene of the accident and ordered safety standards to be raised, but that did little to quell discontent in the military, Chosun TV reported.
South Korean officials believe the North is trying to "distract" from sinking, ratcheting up tensions against its old Cold War foe.
Marine accidents of a military nature are rarely, if ever, acknowledged.
Late last month, the head of Taiwan's spy agency Tsai Ming-yen said that the Chinese Navy's Type 093, or Shan-class, nuclear-powered submarine had experienced "some sort of accident". last year - the first known public acknowledgment by any government of the incident, which was first rumored to have occurred in August in the Yellow Sea.