Russia and Ukraine exchanged large drone attacks on Sunday night into Monday, with alleged Ukrainian UAVs forcing flight restrictions at three Russian airports.

A Ukrainian drone attack targeted the Smolensk Aviation Plant in western Russia overnight on Jan. 21, starting a fire at the facility, the independent news channel Astra reported. Russian authorities confirmed a drone attack against Smolensk Oblast but made no mention of the plant.

Russia’s military on Tuesday said it would retaliate against Ukraine after Kyiv attacked Russian regions by firing six US-made ATACMS ballistic missiles, six UK-made Storm Shadow cruise missiles and launching one of the biggest drone attacks to date.

A fire erupted in the city of Kazan in Russia's Tatarstan republic overnight on Jan. 20 amid a Ukrainian drone attack on the city, Russian Telegram channels reported.

The barrage appeared to be one of the largest recent assaults in Ukraine’s campaign to damage Russia’s war machine on its home territory.

Ukrainian President Volodymyr Zelenskyy warned allies that the defense of his nation is a litmus test for broader Western resolve.

Ukrainians conducted a drone attack on Smolensk, a city located about 306 kilometres from the Ukrainian border. The governor of the Smolensk region, Vasily Anokhin, confirmed the information about the strike.

Ukraine launched an attack using long-range drones on the Kazan Aviation Production Association named after S.P. Gorbunov (KAPO). This facility, located in Tatarstan, manufactures Russian Tu-160M strategic bombers and Tu-214 passenger planes.

A drone attack by Ukraine has set an oil depot in Russia's Smolensk region on fire, in the latest in a series of strikes targeting Russian energy infrastructure in recent weeks