A large-scale Ukrainian drone attack hit two Russian oil refineries and a military airfield overnight, causing a large fire at one of the refineries that put it out of operation.

The strikes hit “key technological facilities” at two refineries in the southern Krasnodar region, a Ukrainian defence source told AFP.

“The work of the plant has been partially suspended. Exactly 10 UAVs (drones) flew exactly into the plant, there was a strong fire. There may be hidden damage,” Eduard Trudnev, the security director at Slavyansk ECO Group, which operates the Slavyansk plant, was quoted as saying in Russian state media.

Ukrainian drones also targeted the Kushchevsk military airfield, although it was not immediately clear what damage was caused.

Meanwhile Russia launched its own barrage of missiles at Ukrainian power facilities in the early hours of this morning, hitting locations in the centre and west of the country, damaging equipment and injuring at least one energy worker.

Ukraine’s largest private energy company, DTEK, said its four thermal power stations were hit and “serious damage” was caused.