A drone attack overnight on Jan. 14 caused damage to an industrial facility in the city of Engels, located in Russia's Saratov region. Engels lies around 600 kilometers (370 miles) from the front lines in Ukraine.

Ukraine continues to cripple Russia's energy sector by hitting numerous oil refineries, depots, chemical plants, and more with drones.

Ukraine launched waves of long-range strikes, including its ATACMS and Storm Shadow missiles, at targets inside Russia.

Ukrainian drones attacked the Russian cities of Saratov and Engels during the night, damaging an industrial facility, according to Roman Busargin, the governor of the Saratov region.

While the ground war in eastern Ukraine has settled into a grinding war of attrition, where Russian forces sacrifice hundreds, sometimes thousands, of troops a day, for small, incremental advances, the air war has the two sides inflicting significant losses on each other's energy sector.

Kyiv targeted Russian factories developing weapons, an oil depot, a refinery and air defense systems, a Ukrainian official said.

Located in Saratov Oblast, over 750 kilometers from the Ukrainian border, Engels airbase is home to Russian heavy bombers.

Roman Busargin, Saratov regional governor ... while Ukraine will likely plug away with further efforts to damage Russia's oil facilities deep into Russian territory.

Ukrainian drones reportedly caused a significant fire in Russia's Saratov region, targeting the city of Engels. The area is known for hosting a strategic air base used by Russia's nuclear forces. While videos depicted the fire,

Europe warns its airlines to stay away through next summer, as Ukraine turns skies of western Russia into a battlefield.

Volodymyr Zelensky wants the president-elect to bolster Kyiv on the battlefield before opening negotiations with Russia