(Bloomberg) -- Finland’s authorities said Russia’s war in Ukraine and the expulsions of diplomats that followed have hampered Russian espionage operations, causing the country increasingly to turn to the cyber environment for intelligence gathering.

Russia’s traditional method of spying is to use human intelligence under diplomatic cover and that has now “become substantially more difficult,” the Finnish Security and Intelligence Service, Supo, said in a national security overview published on Thursday. It also warned of risks to critical infrastructure.

“We consider it highly likely that Russia will turn to the cyber environment over the winter,” said Supo Director Antti Pelttari. “We nevertheless consider it unlikely that any cyberattack will paralyze critical infrastructure in the near future.”

The security agency also warned authoritarian states “can secure access to or influence over critical infrastructure” via corporate acquisitions or investments, and identified China as a potential perpetrator alongside Russia.

In March, Supo said it expects more Russian spying and influencing operations amid Finland’s plans to join the NATO defense alliance.

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