KYIV/MOSCOW: Ukraine said on Sunday it launched a `large-scale` attack to destroy Russian bombers as it geared up for talks in Istanbul with Moscow counterparts to explore prospects of a ceasefire.

The spectacular claim that Ukraine damaged $2 billion worth of Russian aircraft parked at airbases thousands of kilometres away came as Kyiv announced a Russian military strike killed at least 12 soldiers at an army training site, leading to the resignation of its ground forces commander.

Russia confirmed that several of its military aircraft `caught fire` after a large-scale Ukrainian drone attack, in which suspects were detained. `In the regions of Murmansk and Irkutsk, several aircraft caught fire following the launch of FPV drones from a territory located in the immediate vicinity of the airfields,` the Russian defence ministry said on Telegram, referring to first-person view drones. It added that there were no casualties and that several `participants` had been arrested.

Russia also said two bridges that collapsed in regions bordering Ukraine were brought down by explosions. Officials were treatingthem as `acts of terrorism` but had not immediately accused Ukraine.

The developments followed Russian ground advances in recent days in Ukraine`s border Sumy region and both sides unleashing punishing aerial attacks on the other. President Volodymyr Zelensky said that he was sending a Ukrainian delegation to Istanbul led by his Defence Minister Rustem Umerov for the talks on Monday with Russian officials.

Drone attacks The intensified strikes waged by each side came as Kyiv and Moscow each strived to show themselves coming from a position of strength. A source with Ukraine`s SBU security service said the coordinated attacks inside Russia were `aimed at destroying enemy bombers far from the front`.

The source said Russian airbases in the eastern Siberian city of Belaya, in Olenya, up in the Arctic near Finland, and in Ivanovo and Dyagilevo, both east of Moscow, had been targeted.

Igor Kobzev, Governor of Russia`s Irkutsk region, which hosts the targeted Belaya airbase, said `it`s the first attack of this sort in Siberia`.

On Sunday, Ukraine`s air force said it was hit by 472 Russian dronesand seven missiles overnight a record since the beginning of the invasion.

In a rare admission of its military losses, the Ukraine army said Russia`s `missile strike on the location of one of the training units` had killed a dozen soldiers, most of whom had been in shelters during the attack. `As of 12:50 pm, 12 people are known to have been killed and more than 60 wounded,` it said.

The attack led Ukrainian ground forces commander Mykhailo Drapaty to announce his resignation, saying he felt `responsibility` for the soldiers`deaths.

Blasts fell bridges Back in Russia, officials said a blast brought down a road bridge in the Bryansk region bordering Ukraine on Saturday, derailing a passenger train heading to Moscow and killing seven people. A separate rail bridge in the neighbouring Kursk region was blown up hours later in the early hours of Sunday, derailing a freight train and injuring the driver.

Authorities did not say who was behind the explosions, but investigators said a criminal inquiry was underway.-AFP