Emergency crews are currently on-scene extinguishing the blaze.In the city of Ivano-Frankivsk, shattered windows were reported at a kindergarten as well as a residential building, Mayor Ruslan Martsinkiv reported.Explosions were heard in the northwestern city of Lutsk in Volyn Oblast, and over Vinnytsia Oblast around 4:45 a.m local time, Suspilne reported.Residents also reported hearing sounds of explosions around 5:30 a.m. local time in the city of Khmelnytskyi, according to Suspilne. Ukraine's Air Force warned of missile threats on Ukraine's western and central regions. At 4:50 a.m. local time, Poland announced that it had scrambled military jets to protect Polish airspace amid the Russian attack in western Ukraine.No casualties were reported as of 6:45 a.m.In recent months, Russia has intensified its attacks against Ukraine's critical infrastructure in a renewed assault against the country's energy grid.As a result of the attacks on energy infrastructure, Ukraine began implementing rolling shutdowns on May 15, but they have dramatically increased in recent days.Ukraine war latest: Ukraine claims attack on 4 refineries, Shahed drone storage sites in RussiaKey developments on June 21: * Ukraine attacks 4 refineries, Shahed drone storage sites in Russia, military says * Russia attacking Chasiv Yar from Toretsk direction, military says * Media: South Korea’s level of arms supplies to Ukraine will depend on Russia’s actions, official says * Russian…The Kyiv IndependentElsa Court