According to multiple media reports including The Sydney Morning Herald (smh.com.au) as well as Ministry of Defense of Ukraine, the the Russian Navy reportedly sank one of its own, junked vessels to create an obstacle, a Ukrainian official claimed.
Ukraine Defense Ministry spokesman Lieutenant Colonel Alexei Mazepa was quoted as saying that Russian sailors pulled the anti-submarine vessel Ochakov out of a naval junkyard and sank it in the straits that connect the Black Sea with a body of water known as Donuzlav Lake.
“The Russian Navy Ochakov Kara-class cruiser was sunk . . . to blockade the Ukrainian Navy ships deployed in Novoozerne,” The Ukrainian Ministry of Defense said in a statement. “The Russian military towed and put in the navigating channel their ship Ochakov. They filled her with water. Then, there was some explosion."
The Defense statement explained that water depth in this area is roughly 9-11 meters, and the sunken ship prevents ships from leaving the Donuzlav lake. The statement also said " a lot of time and costs" wil be required to refloat this ship.
The sinking is the latest in a series of moves by Russian naval forces in the area. On Wednesday, the mouth of the bay was blocked by 10 Russian vessels including the guided missile cruiser Moskva.
Russia leases the port of Sevastopol and other bases in Crimea, which serves as the headquarters of its Black Sea fleet.
(Source: Multiple media reports, inlcuding the Los Angeles Times and The Sydney Morning Herald)