Ukraine’s drone attacks on Russian oil refineries are trying to achieve what Western sanctions couldn’t: grinding down what fuels Russia’s war machine and the backbone of its economy in an echo of the Allies' oil bombing campaign on German assets in World War II.

Ukraine's air force said on Thursday it had shot down all 42 drones and one of four missiles used by Russia during overnight attacks. Air defences went into operation in nine Ukrainian regions, the air force said in a statement on the Telegram messaging app nearly 31 months after Russia's full-scale invasion.

The Ukrainian armed forces have deployed a new kind of drone to defend their country, one filled with a pyrotechnic thermite mixture that rains fire down on enemy positions. Its use is highly controversial.