Images of the Sinpo South Shipyard suggest circumstantial evidence of the construction of a new ballistic missile submarine, according to the report on Wednesday. The evidence supports claims last month in North Korean state media, which said that North Korean leader Kim Jong Un had inspected a newly built submarine at an undisclosed location. North Korea is thought to have one Sinpo-class submarine in operation, which launched what is believed to be a KN-11 ballistic missile into the Sea of Japan in 2016.