Sweden's military said it made three reliable sightings of a "foreign undersea" presence as part of its investigation into suspected Russian activity.
A photograph taken Sunday by a passerby showed the top of a submerged object in the waters around Stockholm, The Independent reported. Rear Admiral Anders Grenstad, who announced the sightings, did not confirm if the object is in fact a foreign submarine.
The sightings are part of Sweden's investigation into claims of foreign underwater activity in the Stockholm archipelago, an operation reminiscent of a Cold War probe into possible Soviet submarine activity off Sweden.
Grenstad said on Friday the tips came "from a credible source" but did not specify which foreign power is believed to be involved. However, rumors suggest that a small Russian submarine had somehow suffered damage in Swedish waters and was in trouble, according to the Associated Press.
Russia's Defense Ministry denied any activity in Sweden and said its ships have been "fulfilling their tasks in the world's oceans" as planned, Russian media reported according to the AP.
"There have been no emergencies or accidents with Russian military vessels," an unnamed ministry spokesman told Russian news agencies.
Sweden's investigation comes a month after two Russian warplanes were intercepted in Swedish airspace over the Baltic Sea, prompting Sweden's Foreign Ministry to summon the Russian ambassador to protest the violation.
A similar military incident between Sweden and the eastern European country occurred in 1981 when a nuclear weapon-armed Soviet submarine became stranded off the southeastern coast of Sweden. Eleven days passed before Swedish officials gave the green light for the Submarine to leave its territory, the AP reported.
