In recent days, explosions on various railway tracks in the Russian regions of Belgorod and Voronezh derailed trains. According to official information, no one was injured, but the Russian authorities are investigating suspected terrorism.

The explosions came amid a spate of acts of sabotage in Russia that made headlines around the world and are suspected to be the result of Ukrainian intelligence activities.

Ukraine takes aim at critical targets

Russian railroads transport ammunition and fuel for the army and have already been the target of several acts of sabotage by the two Ukrainian secret services, commonly known by the abbreviations SBU and HUR.

On November 30, 2023, SBU agents blew up a train loaded with fuel in a tunnel on the Baikal-Amur Mainline, in Russia's far east. The fire disrupted the most important supply route in Russia's eastern regions for a number of days.

On June 1, 2025, railroad bridges collapsed in the western Russian regions of Bryansk and Kursk at almost the same time, derailing trains and killing seven passengers. The Russian authorities once again started a terrorism investigation and accused the Ukrainian secret services of carrying out the attack.

Attacks on Crimean bridge

The bridge between the Russian mainland to the Ukrainian peninsula of Crimea, annexed by Russia in 2014, is a central element of Russian propaganda and one of the most important logistical arteries for supplying Russian troops. The SBU has already organized three high-profile attacks on the bridge, which first opened in 2018, repeatedly exposing weaknesses in Russia's defenses.

On the morning of October 8, 2022, a truck loaded with explosives originating from the Russian region of Krasnodar detonated on the two-part structure. Parts of the car bridge collapsed over a length of more than 100 meters (some 320 feet). In addition, eight diesel tanks on the railroad tracks next to the bridge caught fire.

"The operation was planned for six months and the explosives were transported by fake companies via Georgia, Armenia and  Kazakhstan in order to evade Russian control," explained SBU chief Vasyl Malyuk at the time.

For 22 days, traffic on the bridge was at a standstill, which led to a shortage of fuel and ammunition in Crimea and forced the Russian army to divert its supplies via the occupied territories of the Zaporizhzhia region.

Ukraine continued its attacks the following year, forcing Moscow to reinforce the defense of the Crimean bridge with anti-aircraft systems. But another attack followed shortly afterwards, when two drone boats exploded near bridge piers. Russia had to restrict traffic for a month. The attack marked the beginning of a wave of drone attacks that limited Russia's dominance in the Black Sea.

In December 2024, the SBU attacked a ship transporting construction materials for bridge repairs. Two drones hit the ship directly in the Kerch Strait, destroying the cargo and injuring 15 crew members, according to Russian sources. As a result, Russia had to step up its patrols there.

Less than six months later, on June 3, 2025, the SBU placed underwater mines on pillars of the Crimean bridge and detonated them from a distance. Kyiv reported that agents had mined the pillars, but Russian media denied reports of serious damage. Traffic across the bridge was temporarily interrupted.

Targeting airfields

Russia's strategic air forces have played an important role in the missile attacks pounding Ukraine from the very first day of the war. As a result, airfields emerged early on as a top priority target for the SBU and HUR.

The first significant operation was when first-person view drones damaged a radar aircraft stationed at an airfield in Belarus. It had to be repaired at great expense. Kyiv initially denied involvement, but in March 2024 Vasyl Malyuk admitted that two Ukrainian drones had been involved.

Several months later, in August, the HUR attacked the Soltsi airfield in the Novgorod region deep in the Russian hinterland. At least one bomber was damaged and there were also casualties on the Ukrainian side. According to the HUR, its reconnaissance unit was ambushed while returning to Ukrainian-controlled territory and a lieutenant colonel was killed.

The most spectacular plot to date took place on June 1, 2025. Entire swarms of drones, 117 in total, simultaneously attacked four airfields in different parts of Russia. Ordinary trucks, whose drivers knew nothing about the secret cargo, brought them close to the bases.

According to the SBU, 41 aircraft were destroyed during Operation Spiderweb, including 34% of Russian cruise missile carriers. According to NATO, over 40 aircraft were damaged, 10 to 13 of which were completely destroyed. Russian sources reported fewer losses.

Drones instead of missiles

In July 2023, the SBU attacked the city of Moscow, with two drones built from light aircraft hitting buildings. The drones didn't cause significant damage, but panic ensued in the Russian capital.

According to the Reuters news agency, air defenses were ineffective against small drones, prompting security measures in Moscow to be tightened.

Following this strike, drone attacks became commonplace and records were repeatedly set for range. In April 2024, for example, a HUR drone flew 1,200 kilometers (745 miles) to Nizhnekamsk in the Republic of Tatarstan, where it set fire to an oil refinery and brought production to a partial standstill.

In June 2024, SBU drones attacked "Voronezh" radar stations in the Orenburg region, which were part of the early warning system for missile attacks following a flight of around 1,800 kilometers.

High-ranking targets

The SBU and the HUR have also targeted and assassinated suspected collaborators, Russian officers or engineers involved in missile attacks on civilian targets.

It is known that the SBU killed the commander of the Russian forces for defense against radiological, chemical and biological threats, Lieutenant General Igor Kirillov, and one of his associates in Moscow in December 2024. Kirillov was accused of war crimes, including attacks with chemical weapons on Ukrainian defense forces.

Earlier this year, Ukrainian agents in Moscow shot and killed Mikhail Shatsky, the deputy head of the Moscow Experimental Design Bureau Mars, which was responsible for the modernization of missiles and the development of new drones. The operation was confirmed by Ukrainian military intelligence, but without providing any details.

This article was originally written in German.