The Swedish Coast Guard said on Thursday it boarded and took control of a suspected stateless vessel in Swedish waters of the Baltic Sea, in the second such incident in less than a week.
The 228-metre (250-yard) tanker Sea Owl I was flying the Comorian flag, and the coast guard said it suspected the ship was sailing under a false flag.
The ship is also on the sanctions list of several countries, including the EU.
"The threats to maritime safety and the environment are too high," said Daniel Stenling, Deputy Chief of Operations at the coast guard. "Therefore, there is reason to intervene against the vessel."
Sweden's minister for civil defence, Carl-Oskar Bohlin, said in a post on social media the ship was suspected of belonging to the Russian shadow fleet.
The boarding took place off the coast of the southern Swedish town of Trelleborg.
On Friday, the coast guard boarded the ship Caffa, which was sailing under a Guinean flag, near Trelleborg.
(Reporting by Supantha Mukherjee in Stockholm; Editing by Chris Reese)
