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

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.

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.

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

Ukraine claimed Saturday to have struck one of Russia’s largest oil refineries in a drone attack, starting a fire at the facility more than 700 miles into Russian territory.

Ukraine used long-range drones to attack the Kazan Aviation Production Association named after S.P. Gorbunov (KAPO). These are aviation plants in Tatarstan where Russian Tu-160M strategic bombers and Tu-214 passenger planes are manufactured.

In Russia, a series of explosions occurred on the outskirts of Ryazan and Kazan. Due to an attack by strike UAVs, air defense systems are active over the cities, RBC-Ukraine reports, with reference to Russian Telegram channels and public sources.

The Borisoglebskoye experimental airfield, which houses the Kazan State Aviation Plant, the manufacturer of Tu-160 strategic bombers, was the possible target of the attack, along with the helicopter factory in the Aviastroitelny district of the city.

A fire broke out in Kazan, the capital of Russia's Tatarstan republic, early on January 20 during a reported Ukrainian drone attack, according to Russian Telegram channels. Videos circulating on social media show a large fire engulfing parts of the city,

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. Videos postedto social media appear to show a large fire ablaze following a drone attack.