Three of North Korea’s tankers moving Chinese oil changed their routes in April, heading to a much more distant terminal, according to the NK News ship tracker and data from Marine Traffic.

The three DPRK flagged tankers eschewed their usual delivery route, from Dalian to Nampho, instead heading south to a large oil terminal at Yangshan, near Shanghai.

The journey is approximately three times longer than the Dalian route, and would be a stretch for North Korea’s small coastal tankers.

“My gut reaction would be the cargo, whatever it is they