The Swedish Navy is poking around the waters of the Stockholm archipelago after a mysterious submarine was sighted three times in the surrounding area over the past several days.
A four-day search has turned up nothing thus far, but some Swedes are directing serious side-eye at Russia, whose military aircraft have continually violated Swedish air sovereignty over the past several months. In September, it prompted then-Swedish foreign minister to place a formal complaint with the nation's Russian embassy, a rare flare of anger in Swedish foreign policy.
Not us, says Russia. A Russian Defense Ministry spokesperson has already pointed a finger at the Netherlands; a Dutch submarine was conducting annual exercises near Stockholm last week. But that submarine left for Estonia on Thursday, before the other mystery vessel had been sighted.
The Dutch have reportedly denied that their submarine is in Swedish territory.
Russia has a base in Kaliningrad, between Lithuania and Poland, which faces Sweden and supports several submarines, according to the BBC. Soviet Union submarines caused alarm several times within Sweden during the 1980s after vessels entered Swedish waters. Tensions in the Baltic region has increased as a result of months-long violent conflict between Russia and Ukraine, and escalated further after an Estonian intelligence officer was held by Russia in September, supposedly on suspicion of spying.
Sweden expanded the search to include more territory on Monday, and the navy is using ships and helicopters to patrol the waters of the archipelago. The nation's government also established a no-fly zone above the search area.
Yet assuming the sightings are real, the owner of the submarine likely did not get inside the Stockholm archipelago by accident. The area consists of around 30,000 islands and is farily difficult to navigate.