Tallinn arson, 15 Aug 2026 - Russia blamed

Estonia's government said on September 29 that the fire at a Milrem Robotics building in Tallinn on August 15 was "an act of sabotage commissioned by the special services of the Russian Federation". Prime Minister Kristen Michal said Estonia could say so "with full confidence", 45 days after the fire and 43 days after two of the three suspects were detained in Latvia.

A local resident reported suspicious activity near a Milrem Robotics building on Betooni tänav, in Tallinn's Lasnamäe district, and Estonia's Emergency Response Center logged the fire report at 01:45 local time (22:45 UTC) on August 15, 2026. Fire crews had the blaze under control by 03:03 local time and then removed sections of the roof to find and extinguish remaining hot spots. No injuries were reported. Estonian prosecutors say preliminary evidence points to a deliberate, pre-planned arson at the building used by Milrem, the Estonian maker of the THeMIS unmanned ground vehicle, and three suspects have since been detained in Latvia.

Milrem's THeMIS ground vehicles are already deployed to Ukraine

Milrem Robotics builds robotic and autonomous systems for military and security use, best known for the tracked THeMIS unmanned ground vehicle. The platform has operated in Ukraine since 2022 on logistics runs, casualty evacuation and route-clearance missions. In June 2026, Milrem and Dutch partner VDL Defentec began handing over the first vehicles from a new production line set up to support a Netherlands-funded delivery of more than 100 THeMIS systems to Ukraine. Russia offered a reward in 2022 for the capture of a THeMIS unit, according to Mezha, a marker of how much attention the platform has drawn from the Russian side of the front.

Investigators call the fire deliberate and are examining a sabotage link

Estonian Prosecutor General Astrid Asi said a criminal investigation opened on evidence gathered by the Internal Security Service (ISS, Estonia's domestic intelligence agency known as KAPO) and the North Prefecture, Tallinn's police district, and that the Prosecutor's Office has asked a court to detain the identified suspects. "The investigation is currently in its early stages and possible motives are still being examined, including whether this may have been an attempted act of sabotage," Asi said, per ERR. ISS Director General Margo Palloson said the threat level facing Estonia has not changed in recent years: "Russia poses a long-term existential threat to Estonia, which means we must take into account possible Russian provocations and nonmilitary threats." Prime Minister Kristen Michal confirmed the suspects had been identified and that one line of inquiry concerns Russian involvement, adding that Estonia would "protect our people and our companies by any means necessary."

Estonia named Russian special services as the client on September 29

Estonia's Internal Security Service (KAPO) reached the conclusion after a six-week investigation, Defense News reported. The government said preliminary findings in the criminal case also indicate the arson was commissioned, and that investigators had seized data storage devices and items that may have been used to start the fire, Defence Industry Europe reported.

Foreign Minister Margus Tsahkna announced that Estonia was summoning Russia's chargé d'affaires, Defense News reported. He called the sabotage part of "a broader Russian campaign across Europe aimed at intimidating us and weakening our support for Ukraine", Militarnyi reported. Michal called it "absolutely unacceptable and irresponsible" that Russia was using sabotage to intimidate Europe.

Three suspects were detained in Latvia

Two Latvian citizens were detained in Latvia on August 17 and a third the next day. Estonian State Prosecutor Gardi Anderson said at the time that a Latvian court had granted requests to remand two of them in custody, with a decision on the third expected shortly. "We are working with our Latvian colleagues to bring the suspects to Estonia," Anderson said. She confirmed the fire was intentional and planned in advance but declined to detail the investigation further, saying all possibilities, sabotage included, remain open. All three suspects were handed over to Estonia in September and are in custody. Milrem CEO Kuldar Väärsi told Postimees it was too early to assess the damage to the building.

The fourth hit on Europe's Ukraine-bound defence supply chain in eleven days

Tallinn is the fourth site tied to Ukraine's military supply chain to catch fire, explode, or come under threat within a matter of days this August. On 4 August, an explosive-laden drone was found next to a Ukrainian cargo aircraft at Leipzig/Halle Airport in Germany. On 10 August, a fire tore through the EMCO ammunition plant near Belitsa, Bulgaria. On 13 August, an explosion hit the KNDS Ammo Italy plant at Colleferro near Rome, though Italian investigators ruled out sabotage there within hours. German authorities have since connected the Leipzig/Halle incidents to Russia, Defense News reported. Poland and the Baltic states have separately tightened protection around critical infrastructure this year as officials warn Moscow may seek to stage operations aimed at undermining support for Ukraine.

Wind conditions over Tallinn on 15 August

At 23:00 UTC on 14 August, close to when the fire was reported, the 80 m surface layer over Tallinn showed wind pushing northeast at 18.8 km/h. At 2,000 m the flow pushed east at 31.5 km/h; at 3,000 m it also pushed east, strengthening to 41.2 km/h, a markedly stronger flow aloft than the 18.8 km/h at the surface. At surface level, that flow would have carried smoke from the Betooni tänav building toward the northeast, away from central Tallinn. This reconstruction is based on reporting by ERR, LRT, Kyiv Post and Mezha, and on AirVeto's wind-model data for the event window. How AirVeto builds this field, and where it is reliable, is described on the methodology page.

The criminal investigation remains open. Tsahkna said Estonia would work with allies to increase pressure on Russia, tighten sanctions and look for ways to restrict Russian citizens' travel to Europe, and would strengthen its support for Ukraine.