Moscow, June 21 : A Ukrainian drone crashed into the Ilsky oil refinery in Russia's Krasnodar region, injuring two people and causing a fire, regional authorities said on Friday.

The incident occurred at approximately 4 a.m. on Friday, the Emergency Department of the Seversky district reported. The crash caused damage to utility structures within the refinery. A fire covering an area of 50 square metres was extinguished, Xinhua news agency reported.

"Preliminary reports indicate that two people were injured," the department said.

Krasnodar Governor Veniamin Kondratyev confirmed that administrative buildings at the refinery were damaged.

A boiler house near the Yuzhny bus station in Krasnodar was also affected.

"Regrettably, there are injured workers at these sites. They are receiving all necessary medical assistance," Kondratyev said on his Telegram channel.

Earlier reports from the Krasnodar regional operational headquarters indicated that several municipalities in the region experienced a mass attack by Ukrainian armed forces early Friday.

The operational headquarters also reported that falling debris from a drone caused injuries to four people in Krasnodar.

/IANS