Estonia is investigating whether Russia was behind a suspected arson attack at a Tallinn building used by Milrem Robotics, Prime Minister Kristen Michal said on 18 August.

Officials have not released evidence yet connecting Moscow to the fire.

The fire hit a site used by a defense contractor that makes unmanned ground vehicles, including THeMIS vehicles used in Ukraine. The Estonian investigation into the Milrem fire comes amid suspected or confirmed arson plots against other European factories supplying Ukraine.

Estonian prosecutors said the fire, which began overnight into 15 August, may have been deliberately set. A resident reported suspicious activity nearby. Investigators identified suspects and asked a court to detain them. No one was injured, and Milrem CEO Kuldar Väärsi told the Estonian outlet Postimees that it was too early to assess the damage.

The company executive said the site was not an office building but declined to identify its contents or what was damaged, including whether unmanned ground vehicles were inside. The company has not said whether production or deliveries were affected.

Milrem’s THeMIS vehicles have operated in Ukraine since 2022. By 2023, the company had delivered 15 of the vehicles to Ukrainian forces and border guards. A Dutch-funded order for more than 150 additional vehicles followed in 2025. A new Dutch production line began making them in June 2026 and handed over its first vehicles for Ukraine.

Other factories supplying Ukraine have faced arson

In March, a fire damaged a Czech facility belonging to LPP Holding, which had supplied hundreds of AI-guided drones to Ukraine. Czech authorities investigated possible terrorism and later detained a fourth suspect.

In January, Lithuania charged six people over an attempt to burn a factory supplying radio-wave scanners to Ukraine. Investigators said Russia-based organizers with GRU links coordinated the operation and connected the network to attempted attacks elsewhere in Europe.

Estonia has traced earlier attacks to Russian intelligence

Estonia has also uncovered Russian-directed attacks on its own territory. In 2024, Estonia’s security service detained 10 people over a Russian-coordinated operation that included damaging cars belonging to then-Interior Minister Lauri Läänemets and a journalist and defacing monuments. Officials said the operation sought to spread fear and tension. Journalists from The Insider, Re:Baltica, and Delfi reported how the GRU recruited Baltic residents for vandalism and arson.

In 2025, an Estonian court found that a Moldovan national working for the GRU burned a supermarket as a trial run before firebombing a Ukrainian restaurant in Tallinn. His cousin filmed the second attack.

Those cases explain why investigators are examining a possible Russian role in the Milrem fire, but they do not establish who caused it.