A Russian warship fired warning shots at a northbound Palau-flagged cargo ship in the southwestern Black Sea, for the first time since Moscow pulled out of a grain export deal last month.

Moscow said the patrol vessel Vasily Bykov fired warning shots at the Sukru Okan after the master did not respond to a request to stop the vessel and undergo an inspection.

According to Russia, the ship was headed for the Ukrainian port of Izmail. According to Refinitiv data, the ship is located near the Bulgarian coast and is headed for the Romanian port of Sulina.

After the warning shots, Russian forces boarded the ship with the help of a Ka-29 helicopter, according to a statement from the Russian Ministry of Defense.

After the inspection, the Sukru Okan continued on its way to the port of Ismail, according to the statement.

Mykhailo Podoliak, an adviser to Ukrainian President Volodymyr Zelensky, wrote on Twitter (X) that the incident constituted “a clear violation of the Law of the Sea, an act of piracy and a crime against a non-combatant ship of a third country in the waters of other countries. Ukraine will draw conclusions and choose the appropriate response.”