Klitschko reported explosions and active air defenses in the capital at around 7:20 a.m.Less than an hour later, a drone has been detected approaching the city, the mayor said.The Kyiv City Military Administration said that power shortages may be introduced as a preventative measure as Russia continues to attack energy infrastructure ahead of the upcoming winter months.The capital has been bracing for intensified missile strikes with the coming winter. Russia previously launched a missile strike on Kyiv on Nov. 8 for the first time since early October.In turn, Kyiv has been subjected to drone attacks on a regular basis in the past two months. Experts have previously told the Kyiv Independent this could be a tactic to wear down air defenses ahead of a mass-missile strike targeting the country's already battered civilian energy infrastructure.Russian training exercise sparks mass air strike alert across UkraineIn Kyiv and cities across Ukraine, sirens sounded, people headed to shelters, and emergency blackouts were introduced.The Kyiv IndependentChris York