The Federal Intelligence Service is expressing concern that many Russian speakers seem to be taking a close look at the country's infrastructure - including nuclear power plants, transit tunnels and airports.
Officially, they’ve been visiting facilities as part of an excursion, but a report in the Aagauer Zeitung says some individuals have made several trips.
The intelligence agency says it’s monitoring these trips.
Russian speaking tourists have increased in numbers since the start of the Ukraine conflict.
Canton Aargau is especially vulnerable as it has two atomic plants, major freight rail routes and houses a major fuel depot.
Commentators point out that any sabotage to these installations would have a major impact in Switzerland and beyond.
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