Russian air defenses shot down at least four Ukrainian drones over western regions of Russia on Sunday, the defense ministry said.

Three drones were shot down over Belgorod region and another over the Kursk region, the defense ministry said.

There were no casualties or damage caused by the incidents, the ministry said.

Drone air strikes deep inside Russia have increased since a drone was destroyed over the Kremlin in early May. Civilian areas of the capital were hit later in May and a Moscow business district was targeted twice in three days earlier this month.