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

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

Ukrainian drones struck deep inside Russia in an overnight attack targeting an oil facility serving a military airfield in the city of Engels, nearly 400 miles from the border, Ukraine’s military said Wednesday.

Ukraine launched its "most massive" attack against Russian military and industrial facilities in a range of up to 1,100 kilometers (620 miles) overnight on Jan. 14, the General Staff of Ukraine’s Armed Forces reported.

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

( MENAFN - UkrinForm) Ukrainian drones hit at least two fuel tanks at the Saratov refinery in Russia. This is evidenced by Planet Labs satellite images taken on January 14, available to radio Liberty's Schemes project, Ukrinform reports.

While air raid sirens during visits by foreign leaders have sounded before, it is rare for air defenses to actually have to fight off attacking drones.

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

A Ukrainian drone attack on Friday sparked a fire at an industrial site in Russia some 170 kilometres (105 miles) from the border, authorities said.

Russia claimed it damaged ground infrastructure of one of the largest natural gas storage sites in Ukraine's Lviv region during a series of attacks on the country's energy sector.

Russia launched cruise and ballistic missiles at Ukraine on Wednesday morning in a new massive attack, the Ukrainian Air Force said.A series of explosions were heard in the eastern city of Kharkiv, while air defence systems were active near the city of Cherkasy in central Ukraine,