Sweden confirms foreign submarine entered its waters in October

The Swedish government is now revamping its security policy to ensure it can defend borders “with all means” available. Any powers seeking to test the country’s resolve will face “enormous risks,” he said.

“The government sees this information as very serious and at the same time it calls for action,” Loefven said. “Securing the nation’s borders is one of the most important tasks of any government. We demand that Swedish territory is respected.”

The incident last month triggered a week-long hunt and the biggest military mobilization in Sweden since the Cold War.

Swedish Armed Forces Supreme Commander Sverker Goeransson said it has now been “fully confirmed that a foreign power violated Swedish territory underwater.” Based on sensor data, traces of a submarine on the sea floor, analysis of a photo taken by a private person and other sightings, the navy concluded that at least one smaller submarine entered Swedish waters.

During last month’s hunt hundreds of troops, stealth war ships and helicopters scoured waters off the Swedish capital after reports of foreign “underwater activity”.

The military said then that it was likely that a foreign submarine or divers had been active in the archipelago, but fell short of concluding that there was absolute proof of an intrusion into Swedish water.