Sweden’s biggest submarine hunt since the dying days of the Soviet Union has put countries around the Baltic Sea on edge.
In a scene reminiscent of the Cold War, Swedish naval ships, helicopters and ground troops combed the Stockholm archipelago for a fourth day Monday for signs of a foreign submarine or smaller underwater craft that officials suspect entered Swedish waters illegally.
Although Sweden has not linked any country to the suspected intrusion, the incident sent a chill through the Baltic Sea region, where Russian forces have been accused of border violations on land, sea and air in recent months.
Swedish military officials say there have been three sightings of the elusive craft since Friday, just 25 miles west of Stockholm.
On Sunday, they released a photograph taken at a distance of what they said could be the mystery vessel — a dark speck surrounded by foaming water.
Military spokesman Jesper Tengroth said that more than 200 personnel were involved in the operation, but he stressed that, unlike Sweden’s submarine hunts in the 1980s, the military wasn’t using depth charges or other anti-submarine weapons.
Speculating on whether the suspected underwater intruder was linked to a mother ship, Swedish media zeroed in on an oil tanker owned by the Russian company Novoship, which had been circling near Swedish waters. On Monday, Novoship President Yuri Tsvetkov said that he was “flattered” by the attention but that the ship was charted for transporting oil from Russia to the United States and was drifting on standby awaiting loading orders.