Kyiv said Thursday that it had seized a foreign cargo ship and detained its captain, alleging that the vessel had illegally exported Ukrainian grain from the annexed Crimean peninsula.Since Russia's capture of swaths of agricultural land in Ukraine in early 2022, Kyiv has accused Moscow of illegally harvesting and shipping grain produced on occupied territory to third countries.The Ukrainian prosecutor general's office said it had "seized" a foreign vessel in the Odesa region that had earlier exported agricultural products via the Crimean port of Sevastopol — a key military hub for Russia in the Black Sea.The Security Services of Ukraine (SBU) said in a separate statement that it had detained the ship's captain, accusing him of violating rules on entering occupied territory.It also claimed that the grain exported by the vessel — Usko Mfu — had been produced in southern Ukraine.The charges carry a maximum penalty of five years in prison, the SBU said, while prosecutors identified the captain as a citizen of Azerbaijan, an ex-Soviet country in the South Caucasus.Prosecutors said 12 other foreign crew members were also on board at the time of the vessel's seizure, without elaborating on their nationality or whether they too would face charges.The Cameroonian-flagged vessel illegally docked at Sevastopol in November 2023 and was loaded with more than 3,000 tons of agricultural products "intended for a Turkish company," prosecutors said."To conceal the illegal activity, the ship's Automatic Identification System (AIS) was turned off before entering the port of Sevastopol, which is a gross violation of maritime safety requirements," their statement added.Prosecutors said the ship returned to Sevastopol a second time in May this year.It was seized at the Ukrainian port of Reni, they added, where they discovered documents issued by Sevastopol port authorities.Igor Delanoe — deputy director of the Franco-Russian Observatory — said this was the first time Ukraine had seized an internationally-flagged vessel over the shipments."The signal is that they want to make third countries face up to their responsibilities," he told AFP."From the Ukrainian point of view, these countries are supporting Russia by their silence, while at the same time benefiting from grain that Ukrainians consider stolen," he added.The European Union in May imposed "prohibitive" duties on grain imports from Russia in a bid to cut off revenues to Moscow for its war on Ukraine.The bloc's trade commissioner said the measure would "tackle illegal Russian exports of stolen Ukraine grain into EU markets."The head of Ukraine's southern Kherson region, which the Kremlin claims is part of Russia, said Thursday that Russian forces caused fires on dozens of hectares of Ukrainian land growing grain.He also said that Russian forces had struck a grain storage facility in the region and attacked firefighters who arrived to extinguish the fire with drones.