Heraldo de Madrid - Ukraine strikes Russian bombers ahead of Istanbul talks

The spectacular claim that Ukraine damaged $2 billion worth of Russian aircraft parked at airbases thousands of kilometres (miles) away came as Kyiv announced a Russian military strike killed at least 12 soldiers at an army training site.

Russia also said two bridges that collapsed in regions bordering Ukraine were brought down by explosions. Officials were treating them 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 attack on the other.

President Volodymyr Zelensky said on Sunday that he was sending a Ukrainian delegation to Istanbul led by his Defence Minister Rustem Umerov for the 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 the seriousness of the Russian side 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 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 meeting to be held at leaders' level.

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

- Drone attacks inside Russia -

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.

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.

But the governor of Russia's Irkutsk region, which hosts the Belaya airbase, spoke of a "drone attack" against a village adjacent to the airbase.

"It's the first attack of this sort in Siberia," the governor, Igor Kobzev, said, calling on the population to not panic. He 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, the Ukrainian army -- in a rare admission of its military losses -- said Russia "launched a missile strike on the location of one of the training units" and killed a dozen soldiers, most of whom had been in shelters during the attack.

"As of 12:50 pm (0950 GMT), 12 people are known to have been killed and more than 60 wounded," it said in a statement.

- 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 amassed 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.

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.

The Kremlin said Putin was briefed on the incidents.

Russia has been hit by dozens of sabotage attacks since Moscow launched its full-scale military assault on its neighbour in 2022, many targeting its vast railroad network.

Kyiv says Russia uses railroads to transport troops and weaponry to its forces fighting in Ukraine.

R.Alba--HdM