A fire caused by a drone attack at an oil refinery in Russia’s southern Krasnodar region in the early hours of Wednesday has been doused, Krasnodar Governor Veniamin Kondratyev reported.

No details on the damage caused to the Afipsky refinery, which lies around 15 kilometres to the southwest of the regional capital of Krasnodar, were released.

Unconfirmed reports said a second refinery in the region had also been attacked, but that no fire had broken out there.

Moscow holds Kiev responsible for the attacks on its territory, which have increased in frequency as Ukraine prepares a long-anticipated summer counteroffensive to retake territory seized by Russia.

Kiev has denied responsibility for a drone attack on Moscow this week.

Britain’s Ministry of Defence reported in its daily update on the war that Russia has had little success in neutralising Ukraine’s air defences.

That it has redeployed forces to react to partisan attacks inside Western Russia.

Attempts to generate reserve forces and position them to counter the Ukrainian offensive have “probably been undermined by uncommitted forces instead being sent to fill gaps in the front line around Bakhmut,’’ it said.