Ukraine's SBU security service carried out a record-distance drone strike on a Russian oil refinery located nearly 1,200 kilometres (746 miles) from the border, a Ukrainian defence source said Thursday.

The source told AFP the strike on the refinery in the Russian republic of Bashkortostan was "the SBU's work" and was carried out at a "record range".

The source said the drone had flown a distance of 1,500 kilometres.

The source said there had also been a strike on two oil depots in the Krasnodar region in southern Russia.

"The SBU has once again proved it has powerful technological solutions that help to inflict painful blows on the enemy," the source said.

Russian emergency services said Thursday that there was damage to a pumping station at the Salavat refinery in Bashkortostan, which belongs to Russian energy giant Gazprom.

"There is no fire and no casualties," the emergency situations ministry said on social media.

Local authorities said that smoke rose above the refinery after the drone strike but it was continuing to function as normal.

The attack comes as Russia celebrates the anniversary of the Soviet victory over Nazi Germany.

"This is an attempt to spoil our holiday. We do not intend to give in to provocations. Happy Victory Day!", Bashkortostan republic head Radiy Khabirov said.