There are signs North Korea might be building another Sinpo-class ballistic missile submarine.
Citing recent satellite pictures of the North's Sinpo South Shipyard,. U.S.-based North Korea monitoring website 38 North says parts and equipment have been moved in the staging area near the construction halls.
The website also said a dozen small cranes, used to load supplies onto submarines, have been placed along the edge of the boat basin.
North Korea currently has just one Sinpo-class diesel sub that, at 2-thousand tons, can carry one Submarine Launched Ballistic Missile.