“Russia's hostile actions come at a cost,” said Minister of Foreign Affairs Margus Tsahkna Estonia will close its road border crossing points with Russia from December 1, the country's foreign minister said on Sunday, in response to attacks on defense industry companies in the Baltic nation. On Saturday, eight Latvian citizens were detained after an attempted arson at drone manufacturer Threod Systems, just north of the capital Tallinn, the Estonian Prosecutor's Office said on Sunday. The group aimed to cause an explosion and set the building on fire. Estonia’s domestic intelligence services said the break-in was carried out by Latvians on behalf of Russia's military intelligence agency, the GRU. In September, the agency said the same agency was behind an attempted arson at the offices of autonomous drone developer Milrem Robotics, which is based in Tallinn. A clear message to the Kremlin Estonia now plans to close its road border crossings with Russia from December 1, Minister of Foreign Affairs Margus Tsahkna said. “We are sending a clear message to the Kremlin: Russia's hostile actions come at a cost. The more aggressively Russia behaves, the narrower its room for manoeuvre becomes," he said in a statement. "Any attempt to threaten Estonia's security, sow fear, or act hostilely against us will be met with a decisive response.” The minister said the closure will reduce Russia’s ability to conduct hostile activities against Estonia and dodge sanctions. "This is a clear step towards strengthening Estonia's security and limiting Russia's ability to exert influence," he added. The government will discuss whether the measure will be temporary or permanent next week.