BBCUkraine claims to have hit more than 40 Russian warplanes at several military airfields, in what appears to be one of the most audacious drone attacks so far on Russian aviation.
According to a statement from Ukraine's security service, SBU, "enemy strategic bombers are burning en masse in Russia".
The SBU says Ukraine is conducting "a large-scale special operation aimed at destroying enemy bomber aircraft."
Dramatic footage has emerged purportedly showing a drone attack at Belaya airbase in Irkutsk oblast, Siberia, thousands of miles from Ukraine.
Russia's military has not commented on the issue.
Reports suggest aircraft were also attacked at the Olenya airbase, near the city of Murmansk, in the far north-western part of Russia.
A source told BBC Ukraine that aircraft including strategic nuclear capable bombers called Tu-95 and Tu-22M3, as well as A-50 early warning aircraft were hit.
Russian media are reporting the attack in Murmansk but says air defences are working. The attack in Irkutsk is also being reported.
Meanwhile, the Ukrainian authorities say 472 drones and seven ballistic and cruise missiles were involved in a wave of attacks on Ukraine last night.
This would appear to be one of the largest single Russian drone attacks so far. Ukraine says it "neutralised" 385 aerial targets.
In a separate development, Ukraine's land forces said 12 of its military personnel were killed and more than 60 injured in a Russian missile strike on a training centre.
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