A major Ukrainian drone attack struck an ammunition depot in Russia’s Tver region early Wednesday, causing significant explosions and fires in the city of Toropets, approximately 240 miles west of Moscow. According to multiple sources, the depot was part of a facility operated by Russia’s Ministry of Defense, housing advanced missile systems and artillery ammunition crucial to Moscow’s ongoing war in Ukraine.
The attack took place around 3:30 a.m. local time on September 18. Ukrainian drones targeted the 107th GRAU (Main Missile and Artillery Directorate) arsenal, a key storage site for Iskander and Tochka-U tactical missile systems, guided bombs, and artillery ammunition. Ukrainian intelligence sources told CNN and the Kyiv Post that the operation was carried out by Ukraine’s Military Intelligence (HUR), Security Service (SBU), and Special Operations Forces (SSO). The strike triggered multiple explosions, and social media images show a massive fireball followed by ongoing detonations.
The scale of the explosions is still under assessment, with estimates varying. Ukrainian advisor Anton Gerashchenko stated on X (formerly Twitter) that the explosion was comparable to 1.3 to 1.8 kilotons of TNT. Meanwhile, George William Herbert, an expert at the Middlebury Institute of International Studies, estimated the blast was equivalent to around 200-240 tons of high explosives. Seismologists at Norway’s NORSAR research foundation detected seismic signals, with magnitudes between 2.5 and 2.8, indicating the force of the explosions.
As of Wednesday afternoon, reports suggested that approximately 30,000 tons of ammunition had either exploded or was still burning. Local authorities ordered a partial evacuation of the area due to the fires and subsequent detonations, according to Tver’s regional governor, Igor Rudenya.
NASA satellites captured intense thermal signatures across an estimated five square miles of the site, underscoring the massive scale of the destruction. The Kyiv Independent reported that the depot had “literally been wiped off the face of the earth” in what may be one of the most impactful strikes since Russia’s full-scale invasion of Ukraine in 2022.
Ukraine’s defense ministry did not officially claim responsibility, continuing its policy of non-commentary on operations inside Russian territory. However, sources within Ukraine’s security services suggest that this attack is part of a broader strategy to undermine Russia’s military capabilities by systematically targeting key supply points.
The 107th GRAU arsenal has been a major site for Russia’s military logistics since at least 2015, storing large quantities of artillery shells and rockets, including 122-mm rockets for BM-21 Grad systems and 82-mm mortars, according to Ukrainian OSINT expert Tatarigami. The site had been targeted by Ukrainian drone strikes in the past but never with such significant results.
While Russian air defenses reportedly intercepted some drones, several managed to hit their targets, causing widespread damage. Governor Igor Rudenya confirmed large fires from the debris of drones repelled by local defenses, and emergency services were quickly mobilized to contain the situation. However, reports from the region indicate that the fire is still ongoing, and further explosions could occur.