Washington:
A North Korea-watching website says recent overhead images show two new North Korean frigates, the largest surface combat ships the nation's navy has constructed in a quarter-century.
The website, 38 North, says the frigates could carry one helicopter each and appear designed to counter South Korean submarines or protect fisheries. They are equipped with anti-submarine rocket launchers.
The vessels can be seen in commercial satellite images from December and January. One is berthed at a shipyard in the west coast port of Nampo, the other at a shipyard at the northeastern port of Nanjin.
It's unclear whether the frigates are yet ready for service.
The website's analysis was being published Thursday. It notes North Korea has constructed the vessels despite economic sanctions and reported industrial stagnation.