Ukraine claims to have hit more than 40 Russian bomber planes at a number of military airbases, in one of its most audacious drone attacks since the war began.

Sources from Ukraine’s security service, SBU, told the BBC strategic bombers were “burning en masse” in an operation named “Spider’s Web”, personally overseen by President Volodymyr Zelensky.

The sources said it took a year-and-a-half to organise the strikes: drones hidden in wooden mobile cabins with remotely opening roofs had been placed on trucks brought near the airbases and then fired “at the right time”.

Russia’s military later confirmed Sunday’s Ukrainian attacks in five regions calling them a “terrorist act”.

Meanwhile, Ukrainian authorities have reported a massive overnight drone and missile attack on its territory.

All this comes as Russian and Ukrainian negotiators are heading to Istanbul, Turkey, for a second round of peace talks on Monday.

Expectations are low, as the two warring side remain far apart on how to end the war.

Russian President Vladimir Putin launched a full-scale invasion of Ukraine in February 2022.

Moscow currently controls about 20% of Ukrainian territory, including southern Crimea peninsula annexed in 2014.

BBC sources in the SBU said that four Russian airbases – two of which are thousands of miles from Ukraine – were hit:

• Belaya in Irkutsk oblast (region), Siberia

• Olenya in Murmansk oblast, Russia’s extreme north-west

• Dyagilevo in central Ryazan oblast

• Ivanovo in central Ivanovo oblast

Russia later said it faced attacks across sites in five regions.

The SBU sources said that among the hit Russian aircraft were strategic nuclear capable bombers called Tu-95 and Tu-22M3, as well as A-50 early warning warplanes.

They described the whole operation as “extremely complex logistically”.

“The SBU first smuggled FPV drones into Russia, followed later by mobile wooden cabins. Once on Russian territory, the drones were hidden under the roofs of these cabins, which had been placed on cargo vehicles,” the sources said.

“At the right moment, the roofs were remotely opened, and the drones took off to strike the Russian bombers.”

Irkutsk Governor Igor Kobzev confirmed drones that attacked the Belaya military base in Sredniy, Siberia, were launched from a truck.

Kobzev posted on Telegram to say that the launch site had been secured and there was no threat to life.

Russian media outlets have also reported that other attacks were similarly started with drones emerging from the lorries.

One user is heard saying that the drones were flying out of a Kamaz truck near a petrol station.

The BBC sources in the SBU said that “preliminary estimates suggest that the damage inflicted on Russian aviation exceeds $2bn (£1.5bn)”.

Russian media were reporting the attack in Murmansk but said air defences were working. The attack in Irkutsk was also being reported.

In a post on social media later on Sunday, the Russian defence ministry confirmed that airbases in the country’s five regions were attack.

It claimed that “all attacks were repelled” on military airbases in the Ivanovo, Ryazan and Amur regions. The latter base was not mentioned by the SBU sources.

In the Murmansk and Irkutsk regions, “several aircraft caught fire” after drones were launched from nearby areas, the ministry said.

It said all the blazes were extinguished and there were no casualties. “Some of the participants in the terrorist attacks have been detained,” it added.

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.

Ukraine’s head of land forces, Maj Gen Mykhailo Drapatyi, tendered his resignation shortly afterwards.

He said his decision was “dictated by my personal sense of responsibility for the tragedy”.