Ukraine's military intelligence agency (GUR) claims its operatives have sunk a Russian Black Sea warship in an overnight operation in Crimea.
The GUR said the ship was patrolling the Black Sea near Lake Donuzlav in the occupied region.
It suffered huge damage "as a result of a number of direct hits to the hull," the agency said.
The ship costs between $60m-$70m, the GUR claimed.
It said preliminary information shows a Russian search and rescue operation on the lake was "unsuccessful".
