The Swedish Coast Guard said on Sunday it had seized a tanker in the Baltic Sea ​believed to be part of Russia’s shadow fleet, the ‌latest in a string of similar actions carried out in recent months by the country’s authorities.

The Swedish Coast Guard said in a ​statement that it and police had boarded the Syrian-flagged ​Jin Hui in Swedish territorial waters south of ⁠Trelleborg and begun a preliminary investigation into a lack ​of seaworthiness.

“The coast guard suspects that the ship is sailing ​under a false flag, given there are a number of irregularities concerning its flag status, and therefore does not meet demands for ​seaworthiness as set out in international regulations and agreements,” ​it said.

The coast guard said the ship, whose destination was unclear and ‌was ⁠thought to be carrying no cargo, figured on several sanctions lists, including those of the European Union and Britain.

Read More: Trump likens US navy to ‘pirates’ over Hormuz blockade

Swedish Minister for Civil Defence, Carl-Oskar Bohlin, said separately on X ​that the ​vessel was suspected ⁠of belonging to the Russian so-called shadow fleet.

European nations have stepped up efforts to ​disrupt the so-called shadow fleet of tankers ​used by ⁠Moscow to fund its four-year war against Ukraine. Russia has condemned such moves as hostile.

So far this year, Sweden has stopped five vessels ⁠on ​suspicion of various offences, including oil ​spills and sailing under a false flag, and opened criminal proceedings against ​some crew members.