UPDATED at 10:15 a.m. KST on Aug. 29 and at 12 p.m. KST on Aug. 30: Since the publication of this story, the IMO has removed all registered North Korean military vessels, including all 13 submarines, from its database. In a statement to NK News, the IMO said that updates to its database are made at the request of member states.

North Korea has registered 13 military submarines with the International Maritime Organization (IMO) for the first time, a move that one expert said signals Pyongyang’s intent to show off its naval modernization efforts sending the vessels to visit other countries.