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.

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.

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 Smolensk Aviation Plant produces the Soviet-designed Su-25 ground attack aircraft, as well as Kh-55 and Kh-59 missiles.

Ukrainian drones attacked key military facilities in Russia, including the Smolensk Aviation Plant and a refinery. The information was provided by the General Staff in Kyiv. Ukrainian drones conducted attacks on strategic targets in Russia,

Ukrainian drones attacked key military facilities in Russia, including the Smolensk Aviation Plant and a refinery. This information was provided by the General Staff in Kyiv. Ukrainian drones conducted attacks on strategic targets in Russia,

"At 11:18, a strike was recorded in the Shevchenkivskyi district," Synehubov wrote. Read also: Russian forces attack civilian infrastructure in Kharkiv Oblast The attack involved a Shahed kamikaze drone.