Kiev - Russian forces have taken over the Ukrainian minesweeper Cherkasy, the last military ship controlled by Ukraine in Crimea, in an operation in which they used stun grenades and fired in the air, Ukrainian naval sources said on Wednesday. During the operation there was an explosion on board the ship, which was in an inlet called Donuslav Lake, which apparently damaged its engines. “The Cherkasy has been taken over and as the engine was damaged during the raid it had to be towed away by a tug boat to the anchorage,” Ukrainian navy spokesman Vladislav Seleznyov said. There were no injuries and the crew remained on board until the morning when they went ashore. During the take-over, which began on Tuesday evening, the minesweeper used water cannon in an effort to repel the Russian forces who had approached the Cherkasy in speedboats. “Russians threw stun grenades and fired small arms, apparently in the air,” a navy source said. Russian forces have used similar tactics to seize ships and military bases from the last remaining Ukrainian troops in Crimea in recent days as part of Russia’s largely bloodless annexation of the region. Kiev, which calls Russia’s annexation of Crimea illegal, ordered its remaining forces to withdraw for their own safety on Monday, but not all troops have yet left the Black Sea peninsula and some ships have been prevented from leaving. On Monday Cherkasy attempted without success to break to the open sea through a blockade at the entrance to the inlet. The Russian navy blocked the route earlier this month by scuttling three hulks in the channel.