TALLINN — Estonia will close all its border crossing points with Russia from December 1, Foreign Minister Margus Tsahkna said on Sunday, following a suspected sabotage attack on an Estonian defence company that Tallinn blamed on Moscow.

Estonian authorities detained eight people overnight on suspicion of an attempted arson attack on drone maker Threod Systems that they said had been ordered by Russia’s GRU military intelligence service. The eight are Latvian nationals who were arrested on Saturday morning after trying to enter the company’s premises in Viimsi, north of Tallinn. The group intended to cause an explosion and set the building on fire, but the company’s security personnel prevented the attack.

“As a result of the clear evidence that the Russian military intelligence service, the GRU, ordered a sabotage attack against a company in Estonia’s defence sector, Estonia will close all border crossings between Estonia and Russia starting from 1 December,” Tsahkna wrote on X. “Russia must understand that hostile actions against Estonia come with consequences,” he added. He did not specify how long the closure would last or whether an end date had been set.

Prime Minister Kristen Michal said the attack “was averted thanks to heightened security and a swift reaction by law enforcement” and that “the attackers have been detained.” He said he had instructed Interior Minister Igor Taro and the State Chancellery to prepare the closure, and Taro is to propose that the government close all three road crossings — Narva, Luhamaa and Koidula — to pedestrians and vehicles. The closures will take effect at the beginning of December, allowing Estonians currently in Russia to return home in the next two weeks.

The Prosecutor’s Office has requested precautionary measures for five of the eight detainees while the investigation continues. The head of Estonia’s Security Police, Margo Palloson, said counterintelligence services believe the sabotage attempt was coordinated by the GRU. The attack caused no victims and the factory’s production capacity was not affected, although the facilities suffered material damage. Threod specializes in unmanned aerial systems, including long-range reconnaissance and attack drones.

Estonia, a NATO and European Union member state and a strong supporter of Ukraine, currently has three open border crossings with Russia at Narva, Luhamaa and Koidula, which admit pedestrians and freight, according to Estonian public broadcaster ERR. There was no immediate comment from Moscow on Estonia’s accusations or its decision to shut the border crossings. Moscow has regularly denied accusations by European authorities of involvement in sabotage operations.

It is the second attempted arson attack on an Estonian defence company since August, when Tallinn-based Milrem Robotics was targeted.