North Korea is strengthening its submarine force by deploying new Shark Class K-300 submarines with better performance.

US satellite images and other intelligence have confirmed that North Korea is building and deploying new Shark Class submarines.

The 300t-submarines are 5m longer than the existing 34m-long model and are capable of cruising more than 10km/h faster while submerged.

North Korea currently has about 70 submarines and submersibles, of which the Shark Class accounts for 40, according to the Chosun Ilbo.