Russia says it shot down eleven Ukrainian drones near the Crimean peninsula during the night of Thursday. They are also said to have stopped two drones on their way to the capital Moscow.
Two of the drones headed for Crimea are said to have been shot down near the city of Sevastopol and the other two reportedly crashed in the Black Sea.
The alleged attack attempts have not been confirmed from the Ukrainian side.
In recent months, there has been a wave of drone attacks against Russian-controlled territory. In July, Ukraine managed to cause damage to the Kerch Bridge, which connects Russia to the occupied Crimean peninsula.
Ukraine has increasingly started using so-called maritime drones and recently attacked a Russian port where it is said to have damaged a Russian warship.
However, the intensified drone attacks have not been followed by any major successes for Ukraine in the counteroffensive at the front that began in June.