Ukraine’s military has destroyed two bridges within Russia’s Belgorod region in a recent attack that underscored the rising battlefield utility of inexpensive first-person-view (FPV) drones. The bridges were reportedly used by Russia to store ammunition and mines before they were destroyed in late July. The strikes were launched by Ukraine’s 58th Separate Motorized Infantry Brigade.

The Ukrainian military said the two bridges were used by Russia as supply routes for its troops in the Kharkiv region. The bridges were reportedly mined by the Russian military, with explosives ready to blow them up in the event of a Ukrainian incursion.

Mining bridges and then blowing them up is, however, a standard defensive tactic. Ukraine destroyed several bridges heading to Kyiv during the first days of Russia’s full-scale invasion in February 2022 in a bid to slow the Russian advance. Now, in a striking turn of events, Ukraine has reportedly used that same tactic against Russia.

The 58th Brigade became suspicious of one of the bridges after noticing a high level of activity near the structure. “It became clear that something was going on there,” a representative of the brigade told CNN. Standard reconnaissance drones could not operate under the bridge without losing the signal, so the unit used an FPV drone with fiber optics for the job.

It didn’t take long to figure out what was hidden underneath the bridge. “We saw the mines, and we struck,” the brigade representative added. A video shared by the unit shows the drone flying under the bridge, zooming in on the ammo, and then blowing up in a giant explosion.

A second camera that was in place nearby shows the blast from afar. CNN determined that the bridge was inside Russia’s Belgorod region and only a few kilometers from the Ukrainian border with Kharkiv.

Buoyed by its success, the brigade moved on to another bridge in the same area. Sure enough, it also turned out to be mined. The unit launched a second drone, which was similarly blown up by the mines. “(We) saw an opportunity and took it,” the brigade said.

The use of the drones to carry out the attack on the bridges is noteworthy for its sheer audacity and affordability. Each drone used in the operation reportedly cost 25,000 to 30,000 Ukrainian hryvnias ($600–$725).

Ordinarily, destroying bridges located several kilometers away would require expensive guided missiles or precision-guided bombs. For instance, Ukraine has previously used U.S.-supplied HIMARS systems to target key infrastructure in Russia’s Kursk region. Each HIMARS system costs millions of dollars, while individual rockets can cost tens of thousands of dollars.

The drones used in the Belgorod attack were worth less than an iPhone, yet they still allowed Ukraine to blow up two bridges within Russian territory. And Ukraine was able to do it without having to spend its limited supply of Western munitions. In the modern era, it’s a rare example of Russian weapons and technology being used to destroy Russian military infrastructure.

It is not the first time Ukraine has used FPV drones with great effect. In June, Ukraine smuggled FPV drones to the vicinity of Russian military airfields and used them to destroy or damage dozens of aircraft.

“The goal of these kinds of operations is to achieve maximum effect at the lowest cost possible,” Mykola Bielieskov, a military analyst who previously served as the adviser to the commander-in-chief of Ukraine’s land forces, told CNN. The drones have thus far proved to be an economical way for Kyiv to bridge the gap with Russia’s larger military stockpile.

Kyiv’s destruction of the bridges comes as Russia has been making steady gains in eastern Ukraine. At the same time, Moscow has continued its pattern of near-daily missile and drone strikes on Ukrainian cities. Putin has also said that he is not interested in ceasefire talks for now and intends to continue the offensive.

Against this backdrop, the bridge strike was a rare piece of good news for Kyiv. Russian officials have not publicly commented on the attack. But the bridge loss will undoubtedly have a negative impact on Russia’s logistics in the Belgorod region, as it was used to supply its forces near the Ukrainian border.

For Ukraine, the strike also provided a sobering reminder that innovation is key to survival. Western supplies have been limited, and Russian forces enjoy significant numerical superiority over their Ukrainian counterparts. Faced with the constraints, Ukraine has increasingly been forced to improvise, and cheap, civilian drones have proven to be among its most useful tools.

FPV drones are typically made with commercially available parts and then modified by volunteers. Ukraine has even developed drone swarms as an asymmetric way to target Russian warships in the Black Sea.

“Such drones have an undeniable value. With them, we can achieve effects that require munitions that we do not have,” the 58th Brigade representative said. Going forward, Ukraine’s ability to improvise and strike at strategic targets within Russian territory will likely play a decisive role in offsetting Russia’s battlefield advantages. Two destroyed bridges in Belgorod serve as a powerful illustration of that point.