Japan has reported to the United Nations another suspected case of goods being transferred at sea to a North Korean tanker from a small vessel with what appeared to be a Chinese flag, in violation of U.N. sanctions, the Foreign Ministry said Tuesday.

This is the latest in a series of illicit ship-to-ship transfers involving North Korean and foreign-registered vessels, exposed by the Japanese government since late January.

A North Korean tanker and vessel of unknown nationality were spotted alongside each other in the East China Sea in the early hours of May 19 by a Japanese patrol aircraft and were "strongly" suspected of engaging in the banned activity, the ministry said.

(A North Korean tanker, right, is tied to a smaller vessel during what appears to be a transfer of goods on May 19, 2018)
[Japan Ministry of Defense]

Ship-to-ship transfers between North Korean ships and those of other U.N. member states are prohibited by a Security Council resolution adopted last September in response to North Korea's nuclear weapon and ballistic missile testing.

The North Korean tanker was identified as the "Ji Song 6," which was designated in March by a U.N. Security Council sanctions committee as a vessel subject to an assets freeze and prohibited from entering any foreign port, according to the ministry.

The Japanese Defense Ministry released photographs of the two illuminated ships alongside each other on May 19. A photo taken later in the day showed the small vessel flying what appeared to be the red flag of China.

(The North Korean tanker in question)
[Japan Minisory of Defense]