MADRID - An international manhunt for a Russian spy chief accused of plotting assassinations and coups in several countries is shedding light on how Russia’s covert activities have been increasing throughout Europe, according to Western intelligence analysts.

A general of Russia’s military intelligence service (GRU), Denis Sergeev, who is under investigation in Spain for his possible role in supporting Catalonia’s independence drive, also has been accused of masterminding a murder attempt in Bulgaria, according to information sent by Bulgaria’s public prosecutor’s office to Spanish police last week.

FILE - Military forces work on a van in Winterslow, England, March 12, 2018, as investigations continue into the nerve agent poisoning of Russian ex-spy Sergei Skripal and his daughter, Yulia, in Salisbury, England, on March 4, 2018.

British counterintelligence services have long suspected Sergeev of involvement in a similar attempt to poison a high-level Russian defector in Britain, Sergei Skripal. Authorities in the Balkan state of Montenegro, meanwhile, accuse him of hatching plans for a coup to block their country’s recent entry into NATO.

The Kremlin has strongly denied the charges. But Spanish defense analyst Felix Arteaga of Madrid’s Elcano Royal Institute says Sergeev’s activities “fit within the pattern of Russian activity in Europe,” which he said shows signs of “widening.”

“They have moved from covert actions to others that are more for the aim of displaying influence,” Arteaga told the newspaper El Pais.

Part of elite unit

According to European intelligence officials, Sergeev is a senior operative of the GRU’s elite 29155 unit charged with conducting sensitive foreign missions for the Kremlin. His alleged role in recent “black operations” has been traced through records of his air travels, hotel stays and personal contacts with other suspected GRU officers at locations and times that coincide with a series of attacks.

According to Bulgarian authorities, Sergeev, accompanied by another undercover GRU officer, landed in the capital, Sofia, four days before arms dealer Emilian Gebrev, his son and another executive in their company were poisoned with a lethal chemical agent in April 2015.

Bulgarian press reports said the GRU may have wanted to kill Gebrev because he was supplying arms to Georgia, which had a brief war with Russia in 2008.

At least eight Russians were involved in the assassination attempt, according to Bulgarian investigators who have told Spanish police that at least one of them has been identified through an FBI laboratory analysis of images caught on the security camera of an underground parking garage on April 28, 2015. The images show a man in gloves sprinkling powder on the door handle of Gebrev’s car.

Sergeev left Bulgaria two days later, flying back to Russia via Istanbul.

He made two trips to Britain in 2018 on dates that coincide with an attempt to assassinate Skripal using methods similar to those employed against Gebrev.

FILE - Demonstrators wave independence flags in Barcelona, Spain, April 15, 2018, during a protest in support of Catalonian politicians who have been jailed on charges of sedition.

Trips to Barcelona

A false passport that Sergeev used to enter Britain under the assumed name of Sergey Fedotov also has been traced to two trips he made to Barcelona, which Spanish investigators suspect may have involved efforts to penetrate Catalonia’s independence movement.

His two-week stay in Barcelona between September 29 and October 9, 2017, coincided with the October 1 regional referendum on independence, which Spain’s central government considered illegal.

Spanish police investigators say they have no specific evidence of Sergeev’s contacts with separatist groups. But officials of Spain’s defense ministry and other European intelligence agencies have said Russia boosted the independence cause with a propaganda campaign involving hundreds of thousands of social media messages placed by hackers operating from locations in Russia and Venezuela.

Targeting NATO, EU

Hans Georg Maassen, who at the time was Germany’s counterintelligence chief, told an international security conference in 2018 it was “very feasible” that Moscow launched “disinformation” efforts to distort events in Catalonia as part of a larger strategy to weaken NATO and the European Union.

While Sergeev was in Catalonia, the newly formed Republic of South Ossetia — propped up by Moscow in territory forcibly seized from Georgia — opened a consulate in Barcelona that may have been used as a front for Russian activities, according to Spanish intelligence analysts.

During sometimes violent pro-independence demonstrations in November, Spanish police arrested a Russian national in Catalonia carrying a Russian made M-75 grenade in his Belarus-registered car. Spanish press reports quoted police as saying he was being investigated in connection with the Sergeev espionage ring.