MOSCOW

Russia said Wednesday that Ukraine conducted a massive drone attack that started a fire in a large oil depot in the country's western Rostov region and disrupted air traffic in the city of Kazan.

At least four drones were shot down over the Rostov region, its Governor Vasily Golubev said on Telegram, without providing further details about how many hit their designated targets.

Golubev admitted, however, that a fire started in a large fuel depot in the Kamensk district of the region.

"There are no casualties. The emergency services have been engaged in extinguishing fire," he noted.

Meanwhile, an aircraft en route to Kazan was redirected over 200 kilometers (about 125 miles) south to a spare airfield in Samara due to the drone attack threat, according to the press service of Kazan Airport.

"Flights heading to Kazan Airport from Moscow (Sheremetyevo) and Sochi have been redirected to a spare airfield in Samara," the message said.

In a separate statement, the country's Federal Air Transport Agency said that early on Wednesday, temporary restrictions were imposed on the operation of Kazan Airport to ensure the safety of civilian aircraft flights. The airport has temporarily halted flights as of 7.00 a.m. local time (0400GMT).

Similar restrictions were imposed in the city of Nizhnekamsk, also in Tatarstan region, to which Kazan serves as the administrative center.