WASHINGTON — American and European officers imagine that Russian navy intelligence officers directed associates of a white supremacist militant group primarily based in Russia to hold out a current letter bomb marketing campaign in Spain whose most distinguished targets had been the prime minister, the protection minister and international diplomats, in accordance with U.S. officers.

Spanish and international investigators have been trying into who despatched six letter bombs in late November and early December to websites principally in Madrid, together with the official residence of Prime Minister Pedro Sánchez, which additionally serves as his workplace; the American and Ukrainian Embassies; and the Protection Ministry. Nobody was killed within the assaults, which U.S. officers take into account terrorism. An worker of the Ukrainian Embassy was injured when one of many packages exploded.

Investigators in current weeks have targeted on the Russian Imperial Motion, a radical group that has members and associates throughout Europe and military-style coaching facilities in St. Petersburg, the officers stated. They added that the group, which has been designated a worldwide terrorist group by the U.S. State Division, is believed to have ties to Russian intelligence businesses. Necessary members of the group have been in Spain, and the police there have tracked its ties with far-right Spanish organizations.

U.S. officers say the Russian officers who directed the marketing campaign appeared intent on retaining European governments off guard and could also be testing out proxy teams within the occasion Moscow decides to escalate a battle.

The obvious purpose of the motion was to sign that Russia and its proxies may perform terrorist strikes throughout Europe, together with within the capitals of member states of the North Atlantic Treaty Group, which helps defend Ukraine towards Russia’s invasion, stated the U.S. officers, who spoke on the situation of anonymity due to the sensitivities across the investigation. Spain is a member of the alliance and has given navy and humanitarian help to Ukraine, in addition to diplomatic help.

One of many letter bombs was despatched to Instalaza, a weapons maker in Zaragoza that manufactures grenade launchers that Spain is giving to Ukraine, and one other went to the Torrejón de Ardoz Air Base exterior Madrid.

There aren’t any indicators that Moscow is able to have interaction in widespread covert assaults or sabotage in Europe, which Russian officers imagine may provoke a response from NATO and, probably, a expensive wider battle, in accordance with U.S. and allied officers. For that very same purpose, President Vladimir V. Putin of Russia and his generals haven’t ordered a standard assault on a NATO nation.

Mr. Putin’s calculus on terrorist assaults may change if Russia continues to undergo main setbacks in Ukraine, U.S. officers say. Mr. Putin has given his navy intelligence company broad latitude to develop and conduct covert operations in Europe, however the diploma to which the Kremlin was concerned within the letter bomb operation is unclear, they are saying.

“This looks like a warning shot,” stated Nathan Gross sales, the State Division’s counterterrorism coordinator within the Trump administration, when the Russian Imperial Motion was designated a terrorist group. “It’s Russia sending a sign that it’s ready to make use of terrorist proxies to assault within the West’s rear areas.”

The Russian officers behind the bombing marketing campaign work for the Most important Directorate, generally known as the G.R.U., certainly one of Moscow’s extra aggressive intelligence outlets, U.S. officers say. In recent times, the group has carried out daring and deadly covert actions with impunity.

Members of the company have been concerned in a variety of shadowy actions, from interfering within the 2016 U.S. presidential election to taking pictures down a Malaysian civilian airliner over Ukraine in 2014, in accordance with U.S. officers.

One particular a part of the company, Unit 29155, has tried to destabilize Europe via tried coups and assassinations, in accordance with U.S. and European safety officers. Its brokers embrace Russian battle veterans, and it was so secretive that the majority G.R.U. operatives most likely didn’t understand it existed. American and allied officers realized in regards to the unit solely lately.

U.S. officers suspect that the Russian officers concerned within the Spain motion are a part of the 161st Particular Goal Specialist Coaching Middle, whose headquarters in jap Moscow home Unit 29155, amongst different teams, U.S. officers say.

Spanish investigators have recognized “individuals of curiosity” they imagine had been concerned within the assaults, one senior U.S. official stated.

A spokeswoman for the Spanish Embassy in Washington declined to remark, citing the persevering with inquiry.

Fiona Hill, a senior director for Europe and Russia on the White Home Nationwide Safety Council within the Trump administration, stated it could not be stunning if the G.R.U. had directed the Russian Imperial Motion to hold out the assaults.

“Most of those sorts of organizations are after all linked to Russian intelligence, both the G.R.U. or the F.S.B.,” she stated, referring additionally to the Federal Safety Service, Russia’s home intelligence company. “Oftentimes they’re simply entrance teams for the intelligence actions.”

Intelligence brokers use the teams to sow confusion and create “implausible deniability,” she added.

American and British intelligence officers have been working with the Spanish nationwide police and counterintelligence officers on the investigation. Their suspicions in regards to the Russian Imperial Motion and the G.R.U. coalesced late final 12 months, quickly after the bombs had been found, U.S. officers say.

The novel group is simply partially aligned with the Russian authorities. The motion’s management has criticized the incompetence of Russian management within the Ukraine battle and accused Mr. Putin of corruption. But as a result of the group shares Moscow’s goals of undermining Western governments and sowing chaos in Europe, Russian intelligence has been capable of affect its operations, in accordance with American officers.

The flexibility to make use of the Russian Imperial Motion as a someday proxy pressure is helpful to Russian intelligence, notably as a result of that makes it harder for rival nations to attribute actions to the Russian authorities.

The State Division designated the group and its management international terrorists in April 2020, the first time such a label had been utilized to a white supremacist group.

“R.I.M. has offered paramilitary-style coaching to white supremacists and neo-Nazis in Europe and actively works to rally most of these teams into a typical entrance towards their perceived enemies,” the division stated within the announcement of the designation.

The division stated the group had two coaching facilities in St. Petersburg that “are possible getting used for woodland and concrete assault, tactical weapons and hand-to-hand fight coaching.”

The leaders designated by the State Division had been Stanislav Anatolyevich Vorobyev, who based the group in St. Petersburg in 2002; Denis Valiullovich Gariyev, the chief of its paramilitary arm, the Russian Imperial Legion; and Nikolay Nikolayevich Trushchalov, an organizer of the group’s actions overseas.

The division stated that two Swedes who dedicated a collection of bombings in Gothenburg, Sweden, in 2016 had attended a coaching course run by the Russian group. The perpetrators, who had been convicted in courtroom, had focused a refugee shelter, a shelter for asylum seekers and a restaurant.

The Middle for Worldwide Safety and Cooperation at Stanford College describes the Russian Imperial Motion as “white supremacist, monarchist, ultranationalist, pro-Russian Orthodox and antisemitic.” The group advocates the restoration of czarist rule to Russia, it stated, and nurtures ties with neo-Nazi and white supremacist teams in america and Europe.

American and European safety officers have had rising issues about white supremacist teams with transnational hyperlinks for many of the final decade. In 2019, for instance, an Australian man who killed 51 individuals at two mosques in Christchurch, New Zealand, printed a manifesto on-line earlier than the bloodbath saying he had drawn inspiration from white extremist terrorism assaults in Europe and america.

On account of the current letter bombs, U.S. intelligence and counterterrorism officers have elevated their scrutiny of the Russian Imperial Motion, together with updating terrorist watchlists to flag suspected leaders of the group or its members, U.S. officers stated.

Russian intelligence brokers have attracted extra consideration from counterintelligence officers and police departments lately as they’ve carried out more and more daring operations, notably in Europe.

In 2018, they tried to kill Sergei V. Skripal, a former G.R.U. officer recruited by Britain as a spy, by poisoning him and his daughter at their residence in England; these two barely survived, however a British lady died. Russian brokers have additionally carried out bombings and assassination makes an attempt within the Czech Republic and Bulgaria, and tried to drag off a coup in Montenegro, in accordance with European intelligence officers.

The identical elite group energetic in Europe, Unit 29155, has operated in Afghanistan and provided bounties to reward Taliban-linked militants for killing American and coalition troops, in accordance with a U.S. intelligence evaluation first reported by The New York Occasions. American officers stated in 2021 that they had no proof exhibiting the Kremlin had ordered the covert motion.

Charlie Savage contributed reporting from Washington, and José Bautista from Madrid.