Russian container ship in Denmark's grip.

Danish maritime authorities have detained a cargo ship originating from Russia, specifically from the city of St. Petersburg, due to irregularities in its official registration. The Danish Maritime Authority confirmed in a statement on Thursday that the vessel was not properly registered.

The Authority stated that the ship, named “Noura,” claimed to be sailing under the flag of Comoros, but the latter has denied registering the vessel. Danish media reports indicate the ship is flying the Iranian flag and is subject to U.S. sanctions.

According to ship tracking data, the “Noura” departed St. Petersburg in mid-January en route to Egypt. Previous records show the vessel was previously known as “Cyros” and is listed on U.S. sanctions lists. The ship has passed through Danish territorial waters on ten occasions during the past year.

Danish authorities announced they will inspect the ship as soon as weather conditions permit. It is currently anchored in the Kattegat strait north of Denmark.