Aug 13 (Reuters) - A small fire ignited by debris from a

destroyed drone was promptly doused at the Slavyansk oil

refinery in Russia's region of Krasnodar, authorities said on

Wednesday.

Russia's air defence units destroyed 46 Ukrainian drones

overnight, the defence ministry said on Telegram, including five

over the Krasnodar region. The ministry reports only drones

downed, not the number launched by Ukraine.

"There are no casualties reported," the administration said

on the Telegram messaging app. "The fire was promptly

extinguished. Emergency and special services are working at the

scene."

A car caught fire at the refinery, the regional

administration added in its post.

Reuters was not able to independently verify the reports.

There was no immediate comment from Ukraine, which says its

strikes inside Russia aim to destroy infrastructure key to

Moscow's war efforts, including energy facilities.

The Slavyansk refinery is a private plant with a capacity of

around 100,000 barrels per day, supplying fuel for both domestic

use and export.

The overnight Ukrainian drone attack also targeted Russia's

southern region of Volgograd, the regional governor said.

Drone debris fell on a 16-story residential building in the

city of Volgograd, forcing residents to leave their homes, the

governor, Andrei Bocharov, said on Telegram.

The city of Volgograd is the administrative centre of the

broader region of the same name.

The Russian defence ministry said its units destroyed 11

drones overnight over Volgograd.