Two North Korea linked vessels recently removed from a UN sanctions list resumed operations this week, the NK Pro ship tracker shows.

One of the vessels – previously known as the Dawnlight – now has a North Korean flag and is called “Kosan”, according to vessel tracking data provided by Marine Traffic.

The UN Security Council (UNSC) originally added 31 vessels to a blacklist as part of UN Resolution 2270 passed in March last year, but ten have since been removed.

The Dawnlight’s delisting is puzzling given the ship’s longstanding ties to some of the shadier elements of North Korea’s shipping network. The vessel was previously owned by the Singapore-based Senat Shipping, a company blacklisted by the Office of Foreign Assets Control (OFAC) for its ties to North Korea and Ocean Maritime Management (OMM), a North Korean arms smuggler.

According to the UN Panel of Experts (PoE), Senat worked out of the same office as another Singaporean company called Chinpo Shipping, which was found guilty of helping a North Korean vessel smuggle weapons through the Panama Canal in 2014.

“Three other Singapore-registered companies sharing the same office (as Chinpo Shipping), Senat Shipping & Trading Private Limited, Senat Shipping Limited, and Senat Shipping Agency Pte. Ltd., have also undertaken extensive activities on behalf of OMM,” the 2015 PoE report reads.

The Dawnlight’s new North Korean flag and name will do little to ease concerns that the vessel’s DPRK dealings are over.

The ship also appeared on vessel tracking systems near Japan, indicating it probably traveled at least some distance from North Korea without broadcasting its location. While many DPRK-linked vessels exhibit similar behavior, it does not suggest the Dawnlight has turned over a new leaf.

A second, previously sanctioned vessel also returned to work in late January. The Orion Star visited a Chinese port before heading back towards Nampho on North Korea’s west coast.

Why the Orion Star was added to the UN’s blacklist is not immediately clear, though is likely related to its last known owner.

The Hong Kong-based Bene Star Shipping and Trading acquired the vessel in 2013, and is the same organization that took control of the Dawnlight after Senat Shipping was designated by Washington.

Some maritime databases still claim the vessel is sailing with a Mongolian flag, though this information is likely out of date.

Mongolia removed 14 North Korea linked vessels from its registry after the passage of Resolution 2270. Although Mongolia did not release the names of the deregistered vessels, given its blacklisted status the Orion Star was almost certainly among them.

Despite their removal from the UN’s blacklist, both ships are still designated by OFAC.

Flag use by North Korean ships has come under increased scrutiny since the passage of Resolution 2270 in March and Resolution 2321 which followed six months later.

Both documents make it more difficult for North Korea-operated vessels to use flags from other countries, a practice known as using a “flag of convenience” (FOC).