An overnight Ukrainian drone attack on an oil depot near the Russian Black Sea resort of Sochi has ignited a raging fire, as the two countries traded strikes at the end of one of the deadliest weeks in Ukraine in recent months.

More than 120 firefighters were trying to put out the blaze, said the regional governor, Veniamin Kondratyev, as emergency officials reported a fuel tank with a capacity of 2,000 cubic metres (70,000 cubic feet) was burning.

Drone wreckage hit an “oil tank, which caused a fire”, Kondratyev said on the Telegram messaging app. Sochi, which hosted the 2014 Olympic Winter Games, is about 250 miles (400km) from the Ukrainian