Swedish navy sends 200 people to hunt for 'foreign underwater activity' Watch
Sweden has embarked on a huge hunt in the Stockholm archipelago for "foreign underwater activity" in a mobilisation of Swedish ships, troops and helicopters unseen since the Cold War.
The search in the Baltic Sea less than 30 miles from Stockholm began on Friday and reawakened memories of the final years of the Cold War when Sweden repeatedly hunted suspected Soviet submarines along its coast with depth charges.
There is now increasing tension with Russia among the Nordic and Baltic states – most of them European Union members – over Moscow's involvement in the Ukraine crisis. Finland last week accused the Russian navy of interfering with a Finnish environmental research vessel in international waters.
The Swedish military has said information about suspicious activity came from a trustworthy source, without providing details, and that more than 200 military personnel were involved in the search.
The Swedish daily Svenska Dagbladet, citing unidentified sources with knowledge of the hunt, said it began after a radio transmission in Russian on an emergency frequency.