North Korea has reportedly registered 13 of its submarines with the International Maritime Organization (IMO). 

According to the Voice of America on Wednesday, eleven Sang-O-2-class submarines, the Sinpo-class 8.24 Yongung submarine and the Sinpo C-class Hero Kim Kun Ok submarine, were listed on the IMO’s Global Integrated Shipping Information System on Tuesday. 

The owner was listed as the Democratic People’s Republic of Korea, North Korea’s official name. 

The IMO assigns unique serial numbers to all ships sailing internationally to ensure maritime safety, prevent pollution and eradicate maritime fraud. This is the first time the North has registered any submarines with the IMO. 

The North launched the tactical nuclear attack submarine Hero Kim Kun Ok in September 2023. At the time, the South Korean military said it looked like a modified version of the existing Romeo-class submarine.