The U.S. State Department on Friday released a series of notated images further detailing purported illicit ship-to-ship transfers (STS) by North Korea-linked vessels earlier in the year.

In evidence released by the State Department’s International Security and Nonproliferation (ISN) Bureau, the U.S. appears to be hoping to build on evidence tying several ships, some designated and some listed as linked to the activity, to sanctions-busting STS transfers.

The UN sanctions committee earlier in the month designatedthe North Korea-flagged Kum Un San 3 and the Panama-flagged Shang Yuan Bao and New Regent, requiring the tankers be de-flagged and prohibited from