Ukraine claimed Tuesday it has sunk another Russian warship in the Black Sea using high-tech sea drones as Kyiv’s forces continue to take aim at targets deep behind the war’s front line. Russian authorities did not confirm the claim.

The Ukrainian military intelligence agency said a special operations unit destroyed the large patrol ship Sergey Kotov overnight with Magura V5 uncrewed vessels that are designed and built in Ukraine and laden with explosives. The patrol ship, which Ukraine said was hit near the Kerch Strait, reportedly can carry cruise missiles and around 60 crew.