Ukraine hit a key Russian airbase used for nuclear bombers in an overnight kamikaze drone strike as part of a consolidated aerial bombardment of several border regions. 

The 'explosions and fire' at the airbase came as pro-Putin sources also accused Kyiv of targeting a nuclear power plant in Kursk region.

Explosions were heard at Engels air base in the Saratov region, home of Vladimir Putin's Tu-160 'Blackjack', Tu-95 'Bear' and Tu-22 strike aircraft, late last night. 

All of these planes are capable of carrying nuclear missiles but have been used to strike Ukraine with conventional bombs throughout the past two years of war. 

Independent Russia media outlet Astra said its sources indicated three out of four kamikaze drones had struck the Engels-2 air base, with multiple explosions from the drones picked up by security cameras. 

Ukrainian media today confirmed that the GUR military intelligence agency had conducted the strikes. 

Regional governor Roman Busargin claimed all the incoming Ukrainian drones were 'eliminated' over Engels - but locals gave contradictory accounts. 

'The air defence system worked promptly and effectively. There were no casualties or damage to infrastructure from falling debris,' Busargin insisted.

But resident Danil Arkhipov told media this morning: 'I live very close to the airfield. It was hit once the others were shot down by the air defence. 

'Then the ambulance, police and fire fighters with lights flashing were seen.

'The alarm siren is still screaming and something is quietly exploding at the airfield. Seems like something is burning.'