KYIV, Jan 25 (Reuters) - Ukrainian drones attacked a Rosneft-owned oil refinery in southern Russia in the latest such strike on Russian energy infrastructure, a Ukrainian source said on Thursday.

The attack caused a fire overnight at the export-oriented unit in the town of Tuapse, but local Russian officials said early on Thursday that it was extinguished.

"The vacuum unit was on fire. According to preliminary information, there were neither casualties nor injured," Sergei Boiko, the head of Tuapse district, said on Telegram.

Rosneft, Russia's largest oil producer, has not commented.

The Ukrainian source said the SBU security service hit the refinery with drones and would continue attacking facilities providing fuel for Russia's nearly two-year invasion.

"The SBU strikes deep into the Russian Federation and continues attacks on facilities which are not only important for the Russian economy, but also provide fuel for the enemy troops," the source told Reuters.

Unofficial Telegram channels showed pictures of the blaze and also said drones had been responsible.

The plant's annual capacity is 12 million metric tons (240,000 barrels per day). It produces naphtha, fuel oil, vacuum gasoil and high-sulphur diesel, and supplies fuel mainly to Turkey, China, Malaysia and Singapore. (Reporting by Ronald Popeski and Tom Balmforth; Writing by Vladimir Soldatkin; Editing by Andrew Cawthorne)