(Reuters) -Russia's Federal Security Service (FSB) said on Thursday it had found traces of explosives on board a foreign vessel en route from Turkey to Russia that had previously entered a Ukrainian port.

       In a statement on its website, the FSB said that the BMO River, which had been travelling between the Turkish port of Sinop and Russia's Rostov-on-Don, had been ordered to leave Russian waters. The FSB said the ship had twice in June and July entered the Ukrainian port of Reni.

       It was the second such announcement this week involving a foreign ship heading to Russia to pick up grain. The FSB said on Monday that it had found traces of explosives on another ship travelling from Turkey to Rostov-on-Don.

       Russia last week pulled out of the Black Sea grain deal, which had allowed Ukraine to ship food from its southern ports despite the war, and said it would consider all ships travelling to Ukraine to be potentially transporting military cargo.

       (Reporting by Felix Light; Editing by Mark Trevelyan)