Tokyo’s Ministry of Foreign Affairs (MOFA) on Tuesday released photos of a suspected ship-to-ship transfer involving a North Korean vessel, the third case in a month of the illicit trade being caught on camera by Japanese authorities.

In a statement, the foreign ministry said the Japan Maritime Self-Defense Force (MSDF)’s P-3C aircraft and the escort vessel SENDAI spotted the possibly illicit transaction in the East China Sea on Friday afternoon.

The North Korean flagged tanker Yu Jong 2 was spotted “lying alongside a small vessel of unknown nationality” around 250 km from Shanghai.

In photos taken by the Ministry of Defense