Norway's government has said it has expelled 15 Russian diplomats from the country, after they were suspected of spying while working at the Russian Embassy in Oslo.
Foreign Minister Anniken Huitfeldt said the move was “an important measure to counter and reduce the scope of Russian intelligence activities in Norway, and thereby secure our national interests.”
The minister declined to say whether the government was acting in response to a specific incident.
However, the government said the activities of the expelled diplomats were “incompatible with their diplomatic status.”
Ms Huitfeldt said the Russian diplomats must “must leave Norway within a short time."
"We will not grant visas to intelligence officers who apply for a visa to Norway," she added.
“We are not talking about regular diplomats, but intelligence officers under diplomatic cover. Their activities are a threat to Norwegian interests."
Norwegian newspaper VG described Thursday’s expulsions as the most the Scandinavian country has ordered at one time involving Russian diplomats.
The Russian Embassy in Norway called the Norwegian government's decision “an extremely unfriendly step” and promised Moscow would take “retaliatory measures".
In response, Ms Huitfeldt said: “Russia has no reason to respond.
"We have Norwegian diplomats stationed in Russia, but none of them are undercover intelligence officers.”
She also called Russia “an unpredictable neighbour” and “many European countries in the past year have expelled hundreds of Russian intelligence officers under diplomatic cover.”
But Ms Huitfeldt stressed that the government in Oslo wants “normal diplomatic relations with Russia, and that Russian diplomats are welcome in Norway.”
NATO-member Norway has a 198 kilometre-long (123 mile) border with Russia in the Arctic.
VG said that including the expelled diplomats, Russia had about 40 people working at its missions in Norway, which include the embassy in Oslo and consulates in Kirkenes and Barentsburg.
Barentsburg, located on the remote Arctic archipelago of Svalbard, is a Russian coal-mining town of about 500 people.
A year ago, Norway expelled three Russian diplomats it identified as intelligence officers.
A man whom the Norwegian Police Security Service alleged used a false name and identity while actually working for one of Russia’s intelligence services also was arrested last year.
He is awaiting trial in Norway.
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