Prosecutor General Astrid Asi said at a press conference on Sunday that there was an attempt to break into Threod Systems' property in Viimsi, north of Tallinn, to start a fire at 3.06 a.m. on Saturday (November 14).

The incident was thwarted thanks to the intervention of Threod's security team, Asi added.

Internal Security Service (KAPO) Director General Margo Palloson said counterintelligence had confirmed that Russia was behind the attempted attack and that it was coordinated by Russia's military intelligence agency, the GRU.

"This was yet another attempt by Russia to carry out an act of sabotage in Estonia," he told the assembled media.

The attackers attempted to break the building's windows and pour flammable liquids inside to set the building on fire and cause an explosion, Palloson said. "We assess that if this attack had succeeded in the way the attackers planned, it would have caused very significant damage to the company," he said.

Palloson said no one was injured in the incident. The company did not suffer any significant damage, and the production and delivery capabilities were not affected, he added.

Eight detained, five arrested

Eight people have been detained, all residents of Latvia, by the Estonian Internal Security Service (KAPO) and the Police and Border Guard Board (PPA).

"The Prosecutor's Office submitted an application to the court for the arrest of five suspects. The task of the criminal proceedings now is to establish the circumstances surrounding the organization of the attack, the roles of those involved and possible links to other individuals," Asi added.

Palloson said Latvia's State Security Service (VDD) and Prosecutor's Office have contributed significantly to establishing the circumstances surrounding the case.

Threod Systems produces both long-range reconnaissance and attack drones. 

This is the second known attempted arson attack on an Estonian defense company this year.

 In August, a fire was reported at defense contractor Milrem's office in Tallinn's Lasnamäe district, which KAPO also attributed to the Russian special services. Several Latvian citizens were also arrested in connection with the case.

Several other defense industry companies across Europe have also been targeted in recent months.

KAPO has said Russia is aiming to sow fear in society and among businesses, disrupt and weaken defense industry companies' production and technological development, and prevent defense industry products and technology from reaching Ukraine. 

Palloson explained that one of the GRU's methods is to recruit European Union residents who can move freely within the EU's Schengen Area to carry out physical attacks and acts of sabotage.

Perpetrators are recruited from criminal circles and among people in difficult socioeconomic circumstances, he said.

Estonia preparing to close Russian border

Prime Minister Kristen Michal (Reform) on Sunday requested that the "necessary steps" be taken to close Estonia's eastern border with Russia in response to the attacks.

"Closing the border would reduce the threat to people in Estonia and send a clear message that attacks on Estonia's defence industry and defense capabilities are unacceptable," he said in a statement.

Minister of the Interior Igor Taro (Eesti 200) said he will propose that all Estonia-Russia road border crossing points shut from the start of December.

"Estonia has already significantly restricted traffic to and from Russia at our border crossing points, warning each time that further escalation could result in a complete closure of traffic. Now that moment has arrived," he said.

Estonian citizens in Russia will have two weeks to return home, the minister added,

It is not yet known if the closure will be temporary or indefinite.

The Ministry of Foreign Affairs said Estonia's road borders will close on December 1.

Estonia will close all Estonian-Russian border crossing points as of 1 December. Russia's attempts to intimidate, destabilise, or undermine our security will come with a price. We will take every necessary step to protect Estonia's security.

— Estonian MFA | #StandWithUkraine (@MFAestonia) November 15, 2026

This story was updated to add comments from Internal Security Service (KAPO) Director General Margo Palloson and additional details about the incident. Then, for a second time, to add comments from Kristen Michal and Igor Taro.

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