The bombardment comes as Russian forces continue their monthslong campaign to capture the key Donetsk strongholds of Pokrovsk and nearby Chasiv Yar, fighting their way across farm fields and woodland and engulfing small rural settlements.

Officials say a Russian drone has blasted a hole in an apartment building in northeastern Ukraine during a nighttime attack that killed at least six people and wounded nine others

Poland scrambled fighter jets and put its ground-based air defense system on "the highest state of readiness" Saturday morning.

"Attention: Due to the attack by the Russian Federation, targeting locations including those in western Ukraine, Polish and allied aviation operations have commenced in our airspace," informed the Operational Command of the Armed Forces.