Ukraine has blown up scores of Russian nuclear bombers in a mass drone attack on airfields across Russia.

At least 40 war planes have been destroyed in what has been described as ‘the worst day in the history of the Russian air force’.

The operation – codenamed ‘Spider Web’ and in planning for a year and a half – was launched by Ukraine’s Security Service (SBU) on Sunday.

It targeted airfields thousands of miles from the frontline,sources told the Kyiv Independent.

Russian Belaya Air Base in Irkutsk region,Siberia,was ablaze today after a suspected drone strike linked to Ukraine (Picture: Svodka38/e2w)

The drones are understood to have been launched from trucks near to the airfields.

‘Enemy strategic bombers are burning en masse in Russia — this is the result of a special operation by the SBU,’ the source said.

Video appears to show scores of strategic and nuclear bombers being hit at Olenya air base,in the Arctic,and Belaya base in Siberia.

These airbases had been home to vital military jets,which were relocated further north and east out of the strike zone of Ukraine’s drones.

Ukraine did announce in March that it had developed a drone with a 1,800 mile range,but Belaya Base is 2,500 miles away from the frontline in Irkutsk Oblast.

Irkutsk’s governor later admitted ‘a drone attack on a military unit in the village of Sredny’.

Russian Belaya Air Base in Irkutsk region,was ablaze today after a suspected drone strike linked to Ukraine (Picture: east2west news)

Strikes also blasted Diaghilev airbase in Ryazan Oblast,and Ivanovo airbase in Ivanovo Oblast.

Pro-Putin Telegram channels were flooded by reaction to the strikes,with some commentators calling them ‘Russia’s Pearl Harbour’ and the ‘blackest day in aviation’.

The planes hit by Ukraine are expensive and vital parts of Russia’s arsenal,with A-50 jets costing as much as £260million each.

Russia only has less than 10 of these planes in its possession.

Other planes hit were the former nuclear bombers the Tu-95s,and the more modern Tu-22s and Tu-160s,the largest operational bomber in the world.

Russia launched the largest drone attack on Ukraine since the beginning of the full scale invasion (Picture: State Emergency Service of Ukraine/Anadolu via Getty Images)

Each carry dozens of cruise missiles,including the supersonic Kh-22 missiles which can only be shot down by the U.S.-made Patriot air defense system.

It comes as explosions hit Russia’s railway overnight,leaving seven people dead and dozens injured.

One of the bridges collapsed onto a passenger train in the Bryansk region after being ‘blown up’,the region’s governor said.

A second bridge then toppled down at around 3am local time in the Kursk region while a freight train was passing over it.

The driver and his two assistants were injured during the collapse.

Ukraine’s drone attack was launched on the morning sent a delegation to Istanbul for a new round of direct peace talks with Russia.

Negotiations will be begin tomorrow to find a roadmap to a 30 day ceasefire and a lasting peace.

Explosions saw two bridges collapse in Russia overnight (Picture: REUTERS)

Russia also hit its adversary with the biggest largest drone attack since the full-scale invasion in February 2022.

472 drones swept across the border and struck Ukraine on Sunday.