A week-long search for a suspected foreign submarine in the Baltic Sea off the Stockholm archipelago was called off on Friday after Swedish authorities failed to locate the vessel, according to media reports.

“The hunt is over, and now the time has come to analyze what happened,” Ingela Nilsson, a spokesperson for the Swedish Defense Ministry, reportedly said. “Everyone in Sweden has been talking about the hunt, and people were proud to see our military can conduct a large operation like this.”

Rear Admiral Anders Grenstad, deputy director of operations for the Swedish armed forces, said that the foreign “vessel” that had “violated the Swedish waters” has left, adding that it probably was not a very large submarine.              

Many Swedish defense analysts had suggested that the vessel was a Russian submarine. However, Grenstad said that no particular nation has been “singled out,” according to media reports. 

Russia consistently denied sending a submarine to the region and suggested that the suspected intruder might be a Dutch submarine.

The search operation, which was launched last Friday after the Swedish military reported “several credible sightings” of “strange underwater operations,” had brought back memories of the Cold War, when Soviet ships routinely conducted operations in the Baltic Sea.

“The armed forces have done what they could and took it seriously. People are not afraid,” Nilsson reportedly said, adding that Sweden remained confident in its security.