For months, even as its forces were losing ground on the battlefield at home, the Ukrainian military was planning a stunning assault deep in Russian soil.

On Sunday, remotely operated Ukrainian drones emerged from hiding inside Russia and began wreaking damage. When they were done, at least a dozen military aircraft lay in ruins.

An analysis of videos and satellite imagery by The New York Times shows the extent of the attack.

Strategic bombers in at least two airfields, Belaya and Olenya, were destroyed. In total, Ukraine targeted bases in five regions, according to Russia’s Ministry of Defense, which said attacks on three other locations had been repelled. The Times was not able to verify those claims, but satellite imagery captured on Monday indicates that no aircraft were damaged at two of the other bases likely targeted. No clear satellite imagery or footage existed for the third base.

Belaya air base

A video shared widely online, and verified by The Times, shows a recording of the software responsible for piloting the Ukrainian’s drones as their assault on the Belaya air base began.

The footage captures a drone’s view as it flies over the base toward a line of at least six aircraft before descending toward a Tupolev Tu-95 bomber.

Shortly after, a video shows, two drones launch from containers that appear to be disguised as modular homes mounted on the back of a nearby semi-truck. They fly toward smoke plumes billowing from the base less than four miles away.

Footage from the ground recorded roughly halfway between the semi-truck and Belaya shows more drones flying overhead toward the base. Their flight path indicates they may have come from the semi’s general direction.

Videos taken at the launch site later that day show the containers on fire, their tops lying on the ground nearby. In a statement on Monday, Ukrainian officials said crates that transported the drones were rigged to self-destruct once the drones launched.

To assess the damage at the air base, The Times obtained radar imagery from a space imaging company, Umbra, that can see through cloudy skies. Seven strategic bombers appear to be completely destroyed, very likely four Tupolev Tu-22M and three Tupolev Tu-95 bombers. They were also visible in the drone footage. Chris Biggers, a geospatial analyst, published the same findings previously. The confirmed damage at Belaya signals a blow to Russia’s campaign of using long-range bombers to target Ukraine.

In satellite imagery of the base, likely decoy aircraft consisting of car tires and other materials can be seen. Some of these apparent anti-drone measures were set up over the past months.

Olenya air base

The earliest footage of the Olenya air base verified by The Times captures an attack already in motion.

A screen recording from the Ukrainian’s pilot software shows a drone flying by two smoking Tu-95 bombers. Another Tu-95 is hit by an explosion. Car tires — apparent defensive measures — are visible next to and on top of the wings of at least three of the damaged Tu-95 bombers.

Footage captured moments later shows another Tu-95, as well as an An-12 cargo transport aircraft, ablaze.

At a gas station roughly four miles southwest of the base, a man recorded a video of drones flying through the sky. He claims they have been launched from a truck seen parked down the road.

While the strikes on Sunday subjected Russia to serious strategic losses, analysts cautioned it does not appear to have changed the Kremlin’s resolve to pursue its military goals.