Moscow has informed Stockholm of its annoyance in the wake of revelations of espionage undertaken by Swedish secret services on behalf of the American National Security Agency (NSA) that targeted Russia, reports Svenska Dagbladet. The daily adds that in response, Moscow has already “increased its surveillance of Sweden.”

Revealed by Swedish public television channel SVT, which has seen documents leaked this spring by former NSA agent Edward Snowden, Swedish secret services’ monitoring of Russia “dates back to the end of the Second World War.”

Centred on the Baltic region, since 2009, espionage has notably focused on Russian communications that pass through the country, because “of Sweden’s geographical position and and the fact that we are hub for global Internet traffic. Some 80% of Russian electronic traffic has to pass through here,” the newspaper explains.