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's armed forces said Wednesday they attacked a strategic Russian oil depot overnight used to provide fuel for strategic bombers. A huge fire erupted at the Kombinat Kristall depot in the Russian city of Engels.

A huge fire exploded at the ‘Kristal’ oil complex in the city of Engels after long-range strikes, said Ukraine’s military

Slovakia’s Prime Minister Robert Fico said he wasn’t ruling out the resumption of gas through Ukraine after a deal between Kyiv and Moscow expired at the beginning of this year.

However, Fico says it will cost Slovakia 1 billion euros ($1 billion) a year in higher prices for the gas it uses and 500 million euros in onward transit fees. He has threatened to cut emergency electricity supplies to Ukraine as Russia attacks its power grid,