North Korea-linked shipping activities in May were marked by an increase in the voyages of fuel-carrying tankers and bicoastal trips.

At least 25 ships were detected making DPRK-related voyages from May 1 to May 25, according to NK Pro analysis of Automatic Identification System (AIS) ship-tracking data. Ships are meant to broadcast AIS signals in order to help nearby vessels avoid collision, but those conducting North Korean operations — both DPRK-flagged and foreign-owned — have become adept at tampering with their AIS to avoid tracking.

Significantly, at least six of the detected ships were classified as tankers. The rise in