White nationalist groups working at the order of Russian intelligence agents undertook a letter bomb campaign against Spanish government officials either as a test run for a wider campaign or as a signal of what the Kremlin is willing to do to supporters of Ukraine’s defense, US and European officials believe.

According to the New York Times, letter bombs were sent to the residence of the Spanish Prime Minister; the US and Ukrainian embassies in Spain; the Spanish Defense Ministry; and two other locations in November.  One person, an employee of the Ukrainian embassy, was injured in an explosion; the other devices were intercepted before detonating.  The United States government labeled the bombings an act of terrorism.

Western officials believe the Kremlin directed the extremist Russian Imperial Movement nationalist group, designated a global terrorist organization by the U.S. State Department, to undertake the campaign.  Members of the group have been tracked to Spain and France, and sources say the Russians have met with their counterpart Spanish nationalist groups.  US officials are concerned that the letter bombing effort is meant to intimidate Western leaders supporting Ukraine’s defense against Russian invaders, using third parties with ties to the Russian intelligence agencies and military to carry out the attacks rather than direct government sources, which would prompt retaliation.