Ukrainian forces destroyed dozens of Russian warplanes with a drone attack on air bases deep within Russian territory on Sunday.

Ukrainian forces destroyed 40 aircraft in the attack, which an official says took more than a year to orchestrate. Russia’s defense ministry confirmed the attack on Sunday, saying it struck five airfields.

The operation saw drones transported in containers carried by trucks deep into Russian territory, he said. The drones reportedly hit 41 planes stationed at several airfields on Sunday afternoon, including A-50, Tu-95 and Tu-22M aircraft, the official said.

Moscow has previously used Tupolev Tu-95 and Tu-22 long-range bombers to launch missiles at Ukraine, while A-50s are used to coordinate targets and detect air defenses and guided missiles.

A series of explosions also struck bridges in Russia near Ukraine’s border on Saturday, though Ukraine has not taken responsibility for the attacks.

Ukrainian soldiers from the 115th Brigade Mortar Unit conduct mortar training, as members of the Anti-UAV unit test an FPV drone inhibitor in Lyman, Ukraine. (Photo by Jose Colon/Anadolu via Getty Images)

A highway bridge over a railway in the Bryansk region was blown up at 10:50 pm (1950 GMT) on Saturday night just as a passenger train carrying 388 passengers to Moscow was passing underneath, Russian investigators said.

Just four hours later, a railway bridge over a highway was blown up in the neighboring Kursk region, showering the road with parts of a freight train, the investigators said.

Fox News’ Sarah Tobianski, Reuters and the Associated Press contributed to this report.