A Belarusian anti-government organization claims a drone attack severely damaged a Russian military aircraft at an air base near the capital, Minsk.
The report claims the attack took place on Sunday at the Machulishchy Air Base, causing an explosion that extensively damaged the A-50 early warning aircraft.
The group suggested that Belarusians opposed to hosting Russian forces in the country were involved.
Neither Russian nor Belarusian forces have commented.
The British defense ministry said on Tuesday that the role of the A-50 aircraft is to conduct surveillance and coordinate with fighter aircraft. It said the loss of the plane, which is critical to Russian air operations, would be significant.