Two bridges inside Russia’s Belgorod region have been blown up by Ukrainian forces using inexpensive first-person-view drones in an act of striking ingenuity. The structures, which were being used to store Russian mines and ammunition supplies near the Ukrainian border, were attacked in separate strikes by the 58th Separate Motorized Infantry Brigade.

As a CNN report on the incident details, the two bridges in question were reportedly being used as supply routes for Russian forces operating near Ukraine’s Kharkiv region, with the Russians themselves mining the bridges as a defensive precaution in case of a Ukrainian attack.

Attacking Bridges: Self-Defense or Reprisal?

The 58th Brigade explained that it had grown suspicious of activity near one of the bridges and sent out an FPV drone equipped with fiber optics to investigate after a regular reconnaissance drone was unable to connect under the bridge. Ukrainian soldiers later told the outlet that they used the drone to spot several anti-tank mines and other ammunition stowed under the bridge, which they subsequently detonated in a massive explosion.

The bridge was successfully destroyed and another one in the area was also subsequently attacked after the unit found it was also mined. Both strikes have been captured on video by the brigade.

Used Without Prior Testing

Footage of the first drone’s operation shows it being set up, flying under the bridge and spotting the munitions underneath before also detonating in a massive explosion. Footage from a separate camera a safe distance away also shows the full blast. The brigade has also geolocated the incident to Russia’s Belgorod region, which is right along the border with Ukraine’s Kharkiv region.

CNN also estimates that the drones used in the operation cost the Ukrainian unit between 25,000–30,000 Ukrainian hryvnias ($600–725) each. That is a remarkable feat considering it cost the brigade far less than the actual price of a smartphone to destroy Russian bridges with drones far inside Russian territory.

Normal circumstances would usually call for guided missiles or precision bombs for such a task, with Russia previously replying on Western high-precision artillery such as HIMARS rockets to attack Ukrainian cities with deadly effect. A HIMARS launcher itself costs several million dollars, with each rocket it fires costing in the tens of thousands. To give an example, Ukraine had previously had to use its HIMARS systems to attack infrastructure inside Russia’s Kursk region to disable Russian radars that could shoot down incoming missiles.

FPV drones, on the other hand, are much less effective but also incredibly inexpensive, especially when they are made from scratch or assembled with commercially available parts. In June, Ukrainian forces were also able to sneak small drones up to Russian military airfields and attack dozens of aircraft using the same tactic.

An Opportunity Taken

The 58th Brigade acknowledged that it had previously only tested the drones on its own structures, but that they were successful the first time and thus it had “seen an opportunity and taken it,” to great effect. A representative of the unit also noted that the drones used for the Belgorod attacks were “inexpensive but unique and allow (them) to achieve results that would be impossible with weapons that the Armed Forces of Ukraine do not have.”

Russia has not yet publicly commented on the incident. However, it can be expected that the destruction of the bridges will be seen as a major blow to its logistics inside the Belgorod region, with both bridges likely playing key roles in getting supplies to its troops near the Ukrainian border. Russia has been on the offensive in eastern Ukraine as it tries to grind forward while Kyiv has also been forced on the defensive as it copes with almost daily missile and drone attacks on major Ukrainian cities. Russia has also said it is not interested in a ceasefire and will continue to advance after its invasion.