STOCKHOLM — Sweden called off a week-long, multi-million-dollar search for a mysterious underwater craft in its territorial waters near Stockholm after the military said Friday “the intruder” has left the area.
“We have ruled out that it was a large, conventional submarine,” said Rear Admiral Anders Grenstad, deputy chief of the operation, citing depths on nautical charts where sightings were made.
Based on observations and other data collected, Grenstad said there has been “probable foreign underwater activity” but that “the unit or units” were no longer in the area.
It was not possible to say what sort of underwater craft it was or which country it belonged to, he said.
Efforts to determine what caused the intrusion were to continue, including analysis of data collected from underwater sensors and sonars.
During the operation, the military received more than 250 tips from the public.
The search cost an estimated 20 million kronor (2.75 million dollars).
The operation involving navy vessels, helicopters and army units was the largest in years. It began on October 17 after the military said it received credible reports of what it described as foreign underwater activity.
On Sunday, the military released a photo of what appeared to be a partially submerged object.
Most of the naval and amphibious units involved in the search have returned to base and were to remain at a normal alert level, the military said. Some ground forces were to remain in the search area.
The authorities have not accused any country of entering its waters and Moscow has denied involvement after allegations that Russian-language radio calls were intercepted.
During the Cold War, Soviet submarine sightings triggered similar large-scale operations.
Last month, Stockholm protested when two Russian Su24 jets flew into Swedish airspace south of the Baltic Sea island of Oland.
The planes left after a Swedish jet fighter was dispatched to the area.