LONDON, Aug 22 (Reuters) - British military intelligence said on Tuesday (Aug 22) that a weekend drone attack on an airfield deep inside Russia which Moscow blamed on Ukraine is highly likely to have destroyed a nuclear-capable TU-22M3 supersonic long-range bomber.

Kyiv, which on Monday claimed to have attacked another Russian military airfield, says Russia has used the TU-22M3 to bomb targets across Ukraine with conventional munitions. Western military experts believe Russia has around 60 aircraft.

The destruction of the plane, which can be fitted with conventional or nuclear warheads, underscores the vulnerability to drone attacks of Russia's fleet of ageing but lethal long-range bombers that are a major part of Moscow's war effort.

According to satellite imagery reviewed by Reuters, the attack prompted Russia to relocate other planes of the same type from the airfield to alternative bases further from Ukraine.

Unconfirmed media reports said they had been flown to a base in northern Russia.

Russia's Defence Ministry said the attack on Saturday on one of its military airfields in the Novgorod region had been carried out by a Ukrainian drone and that one plane had been damaged. It gave no more details.

Satellite images taken two days after the attack - on Aug 21 - of the same airfield seen by Reuters showed a burnt patch of land, a gap, and judging from the shape, what appears to be the remnants of an aircraft on the tarmac where images of the same site on Aug 8 had shown a military plane.

There was no immediate comment from Ukraine, which rarely takes public responsibility for such attacks, though it has said it will do everything it can to degrade Russian military assets.

Russia, which has designated Britain a hostile country because of its military and financial support for Ukraine, did not comment on the British damage assessment.