Ukrainian drones attack Russian oil refinery in Kaluga region - source

Ukraine attacked a Russian oil refinery in Kaluga region with drones early on Friday, causing damage in an operation that was conducted by the GUR military spy agency, a Ukrainian intelligence source told Reuters.

Ukraine was checking the extent of the damage, the source said. Reuters was unable to independently verify the statement.

Vladislav Shapsha, the Russian governor of Kaluga region, said earlier on Telegram messenger that air defences had shot down four drones in the area where the refinery is located and that there had been no infrastructure damage or casualties.