The Swedish Coast Guard boarded the 182-meter vessel Jin Hui on Sunday amid suspicions it was operating under a falsified Syrian flag, in what officials described as part of ongoing enforcement actions targeting ships believed to be circumventing Western sanctions on Russia.

The Swedish Prosecution Authority said the captain was detained on suspicion of using forged documents and breaching maritime safety regulations, specifically relating to inadequate seaworthiness. Prosecutor Adrien Combier-Hogg said the individual would be interrogated during the day, adding that coordination had been initiated with other national and international authorities.

Sweden’s Civil Defense Minister Carl-Oskar Bohlin said the vessel appears on sanctions lists maintained by the European Union, Britain and Ukraine, underscoring concerns that it may be linked to networks used to bypass restrictions imposed on Moscow following its invasion of Ukraine.

Western officials have increasingly focused on what they describe as a “shadow fleet” of aging, poorly insured vessels with opaque ownership structures, used to transport Russian oil and other commodities outside formal regulatory frameworks. These ships have raised safety and environmental concerns due to their condition and lack of oversight.

Sweden has conducted several recent boardings of vessels in its surrounding waters as part of broader efforts to enforce sanctions compliance and maritime safety standards in the Baltic region.

U.S. Central Command said the vessel, identified as the Sevan, was intercepted by a Navy helicopter launched from the guided-missile destroyer USS Pinckney during operations aimed at enforcing restrictions on Iranian oil and gas shipments.

The military described the Sevan as part of a 19-vessel “shadow fleet” accused of transporting Iranian petroleum products, including oil, propane and butane, to foreign markets in violation of U.S. sanctions.

According to Central Command, the ship complied with orders to reverse course and is now heading back toward Iran under U.S. escort.The interception marks the latest maritime enforcement action under a U.S.-led blockade intended to restrict Iranian energy exports and reduce revenue flows to Tehran amid heightened regional tensions.

U.S. officials said the targeted fleet had been sanctioned by the United States Department of the Treasury for facilitating the transport of billions of dollars’ worth of Iranian energy products through covert shipping networks often involving opaque ownership structures and flag changes.

“These vessels are part of a sanctions evasion network designed to conceal the origin and destination of Iranian exports,” Central Command said in its statement.Since the start of the blockade, the U.S. military said 37 vessels have been redirected, reflecting an expanded effort to enforce sanctions through direct maritime interdiction rather than financial restrictions alone.

The Arabian Sea has become a focal point for such operations due to its strategic role in shipping routes connecting the Gulf, South Asia and global energy markets.Washington has increased pressure on Iranian oil exports as part of broader efforts to constrain Tehran’s regional influence and funding channels, particularly amid ongoing instability across the Middle East and heightened tensions involving U.S. forces in the region.

Iran has repeatedly criticized U.S. maritime sanctions enforcement as unlawful and has accused Washington of disrupting freedom of navigation and international trade.

The latest interception comes as scrutiny of tanker movements linked to Iran has intensified, with governments and shipping regulators monitoring so-called shadow fleets used to bypass sanctions through ship-to-ship transfers and concealed cargo documentation.

No injuries or military confrontation were reported during the interception of the Sevan, and Central Command did not specify the vessel’s final destination before it was ordered to turn back.