"During the air defense of the West group of troops, 48 unmanned aerial vehicles were destroyed in one day," Russia's TASS news agency quoted head of the press center of the troops involved Ivan Bigma as saying.

Kupyansk is a city in the Kharkov Oblast in eastern Ukraine.

Bigma also said that Ukraine suffered up to 145 casualties in the area. Furthermore, Russian fire hit two BMP-1 infantry fighting vehicles, four artillery pieces, a mortar crew and two pickup trucks.

There was no immediate response from Ukraine.