A state of emergency has been introduced in the Russian city of Engels, the governor of the local Saratov region said on Wednesday, after a Ukrainian drone strike hit an oil depot that serves Russia's nuclear bomber planes. In a statement published on Telegram, governor Roman Busargin said that two firefighters had been killed while tackling the blaze. Ukraine launched an overnight strike deep inside Russia that set fire to an oil depot in the city of Engels that serves an air base for Russian nuclear bomber planes, the Ukrainian military said on Wednesday.The governor of the Russian region said Engels and Saratov, on opposite sides of the Volga river, had been subject to a “mass drone attack” and there was a fire at an industrial site, which he did not name. He said there was no word of any casualties.The Ukrainian military reported multiple explosions and a big fire at the “Kristal” oil depot, which it said provided fuel to the “Engels-2” military airfield.For the latest