A sanctioned North Korean oil tanker has been photographed in the process of conducting suspected illegal ship-to-ship (STS) transfers at sea in relay fashion with two unidentified ships, the Japanese Ministry of Foreign Affairs (MOFA) said in a statement Tuesday.

It is the third such instance the North Korean-flagged An San 1 has been observed conducting STS transfers by Japanese Maritime Self-Defense Forces since the ship was designated in March 2018 by the UN Security Council committee in charge of DPRK sanctions.