Sweden's intelligence service on Thursday warned "foreign powers" could try and meddle in the Nordic nation's upcoming general election, singling out Russia in light of alleged interference in the last US vote.
However, the Swedish Security Service (Sapo), which is responsible for tackling espionage and terrorism, said in an annual report that Sweden's "robust" and "decentralised" electoral system was tough to influence.
"It cannot be ruled out that certain foreign powers will take advantage of the Swedish election campaign to enhance conflicts in Swedish society and attempt to weaken the democratic system," said Sapo head Anders Thornberg in the document, which was written last year.
"Russian espionage constitutes the greatest security threat" against non-NATO member Sweden, Sapo warned, adding that a third of Russian diplomats in the country were spies.
"Russia is in Sweden's vicinity and could be linked to a potential military conflict," Johan Olsson, a Sapo chief for countering security threats, said in the report.
Prime Minister Stefan Lofven told a January security conference that a new agency would be formed to protect citizens from "external influence" for the September 9 general election.
"To those who are considering to try to influence the election outcome in our country: stay away!" Lofven said.
"We won't hesitate to recklessly expose those who will try... Russia has been pointed out in many reports," he added.
In a January 10 report, the US Senate accused Russia of spreading "disinformation" and "propaganda" to interfere in the elections of other countries to undermine Western sanctions against Moscow.
Russia's government on Monday insisted there was no evidence that it meddled in the US elections, after Washington indicted 13 Russians for alleged covert efforts to sway voters.