Heraldo de Madrid - Ukraine strikes grounded Russian bombers in major drone assault

In a spectacular claim, Ukraine said it damaged $7 billion worth of Russian aircraft parked at four airbases thousands of kilometres (miles) away, with unverified video footage showing aicraft engulfed in flames and black smoke.

A source in the Ukrainian security services said the drones were concealed in the ceilings of shipping containers which were opened up to release them for the assault.

The long-planned operation came at a delicate moment three years into Russia's invasion.

Ukraine's President Volodymyr Zelensky said on Sunday that he was sending a delegation to Istanbul led by his Defence Minister Rustem Umerov for talks on Monday with Russian officials.

Turkey is hosting the meeting, which was spurred by US President Donald Trump's push for a quick deal to end the three-year war.

Zelensky, who previously voiced scepticism about whether Russia was serious in proposing Monday's meeting, said he had defined the Ukrainian delegation's position going into it.

Priorities included "a complete and unconditional ceasefire" and the return of prisoners and abducted children, he said on social media.

Russia has rejected previous ceasefire demands.

It said it has formulated its own peace terms but refused to divulge them in advance. Russian President Vladimir Putin ruled out a Turkish proposal for the countries' leaders to attend the meeting.

Russian news agencies said the Russian delegation was headed to Istanbul on Sunday for the talks.

- Drone attacks inside Russia -

A source in Ukraine's SBU security service said the coordinated attacks inside Russia were "aimed at destroying enemy bombers far from the front".

Rybar, an account on the Telegram message platform that is close to the Russian military, called it a "very heavy blow" for Moscow and pointed to what it called "serious errors" by Russian intelligence.

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

More than 40 aircraft had been hit at the Belaya base and a fire had broken out there, the source said, showing a video in which several aircraft could be seen in flames and black smoke rising.

AFP was not able to independently verify the claims or the video images.

The SBU claimed in a social media post to have hit Russian military planes worth a combined $7 billion in a "special operation".

Russia's defence ministry confirmed on Telegram that several of its military aircraft "caught fire", adding that there were no casualties and that several "participants" had been arrested.

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

He called on the population not to panic and posted an amateur video apparently showing a drone flying in the sky and a large cloud of grey smoke.

The governor of the Murmansk region where the Olenya base was located, Andrey Chibis, also said "enemy drones" were flying overhead, and anti-aircraft defences were operating.

Russia has been announcing Ukrainian drone attacks on a near-daily basis, usually saying they had all been shot down. But it was rare for such drone strikes to be reported so deep within its territory.

At the same time, Russia has been carrying out constant attacks on Ukraine.

On Sunday, Ukraine's air force said it was hit by 472 Russian drones and 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, and wounded more than 60.

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

- Blasts fell bridges -

Separately on Sunday, the Russian army said it had captured another village in Ukraine's northern Sumy region, where Kyiv fears Moscow could mount a fresh ground assault.

Russia claims to have captured several settlements in the region in recent weeks, and has massed more than 50,000 soldiers on the other side of the border, according to Zelensky.

Authorities in the region have evacuated more than 200 villages amid intensified shelling.

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.

E.Nieto--HdM