An intensive week-long search for a suspected intruder in waters near Stockholm has drawn a blank. The operation to find what was believed to be a Russian midget submarine saw Sweden’s largest naval mobilisation since the Cold War.

The high-profile deployment of corvettes (pictured), minesweepers and fast patrol boats was given credence after several sightings of a mysterious manmade object breaking the surface inside the Stockholm archipelago and the interception by Swedish Intelligence of a coded distress call on a frequency used by Russia. The suspicious movements in the area of NS Concord, a Russian-owned tanker-cum-suspected mothership, added to the intrigue.

The Russian Defence Ministry has denied violating Swedish sovereignty and even suggested the culprit was a Dutch submarine (which happened to be berthed at an Estonian port at the time). Swedes will not be surprised at Russian subterfuge, given the frequency of Soviet submarine incursions into their waters during the Cold War. In 1981 a nuclear-armed Whiskey class submarine became stranded near the naval base at Karlskrona.

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