A once-busy maritime coal smuggling route between North Korea and China has returned to pre-pandemic levels of activity, a joint investigation by NK Pro and the Royal United Services Institute’s (RUSI) Project Sandstone can reveal this week.

Satellite imagery and Automatic Identification System (AIS) ship tracking data show that at least 17 DPRK-linked vessels traveled between North Korea and Zhoushan, China from late April to present. Individual ships often made more than two trips.

Data indicates that North Korean-controlled vessels have continued to transport export coal from the DPRK, despite official denials from Beijing and