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.

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

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

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.

The Russians attacked Ukraine with a new version of the Shahed-136 drones. According to the Defense Express portal, this is the fourth known variant of Iranian drones used by the Russian Federation's army.

Russian forces launched around 550 attack drones, nearly 60 missiles of various types, and more than 660 aerial bombs against Ukraine during the past week, President Volodymyr Zelensky said in his evening address on Jan.

Russia dispatched over 60 drones for attacks on Ukraine, of which 43 were shot down and 15 were electronically neutralised. The heaviest fighting is taking place near Pokrovsk. Russian forces conducted night-time attacks on Ukraine,