Mystery Submarine Hunt Resurfaces Cold War Tensions

Russia claims it isn't their sub off the coast of Stockholm.

— -- Swedish naval ships, helicopters and troops on the ground have expanded their search for what they believe is a foreign submarine in distress not far from their coast.

The search has entered its fifth day.

The alleged submarine has been spotted at least three times since Friday in various parts of the Stockholm archipelago. One spotting placed the vessel approximately 12 nautical miles from the country's capital.

According to The Associated Press, there was an incident in 1981 where a Soviet submarine carrying such weapons was stranded off Sweden's southeastern coast.

The Associated Press contributed to this report.