Andrei Vorobyov was speaking after the defence ministry reported downing two Ukrainian drones in southern Russia.

Ukraine does not claim responsibility for attacks inside Russia.

Russian energy giant Gazprom operates a facility near the village of Gubastovo, about 100 km (62 miles) from Moscow, where the drone crashed.

Gazprom told Russian state-run news agency RIA Novosti that its operations in the Kolomna district had not been interrupted.

The target of the drone in Kolomna "was probably a civilian infrastructure facility, which was not damaged", Mr Vorobyov posted on Telegram.

"There are no casualties or damage on the ground. The FSB (Russian security service) and other competent authorities are investigating," he added.

Images shared by Russian media and officials show a damaged drone in a snow-covered field in front of a forest of birch trees. The area around the Gazprom facility is heavily forested.

The appearance of the drone matches that of the UJ-22 Airborne, a product of Ukrainian manufacturer Ukrjet.

Ukrjet says the vehicle has a range of 800km - enough for it to reach the Kolomna area from Ukraine.

A reverse image reveals no previous matches for the image, suggesting it is recent.

Anton Gerashchenko, advisor to Ukraine's minister of internal affairs, tweeted a photo of the drone.

"It is more than 500km away from Russian border with Ukraine. Soon Putin might get very afraid to show himself in public as drones can reach far distances," he wrote alongside the photo.

If Ukraine was behind the Kolomna drone, it would be the closest attempted drone attack to the capital since Russia invaded Ukraine more than a year ago.

It came as the Russian defence ministry said its forces had downed two Ukrainian drones in southern Russia.

The ministry accused Kyiv of attempting to use drones "to attack civilian infrastructure in the Krasnodar region and the Adygea Republic", adding that they were "neutralised by electronic warfare units".

Moscow has accused Ukraine of being behind attacks on Russian military infrastructure during the war, but Kyiv has not confirmed this.