submarine

The ARA San Juan disappeared last week off the coast of Patagonia. Argentine officials say that they can't confirm that satellite signals received over the weekend came from the sub.

Peter Madsen denies killing her, police say, maintaining that her death was an accident. Wall was researching a story in August on board a submarine he built.

In his first court appearance since his arrest, Peter Madsen said Kim Wall died when a hatch fell on her head. He also denied mutilating her body, which washed ashore later as a naked, headless torso.

Peter Madsen and the journalist set out alone in his submarine. Within days, the sub had sunk and Madsen had admitted that Kim Wall died aboard. Now, police say remains that washed ashore are hers.

Peter Madsen pushed off in his submarine with a Swedish journalist, but by the time he was rescued, she was gone. Now, he says she died onboard — but the admission is stirring even more questions.

The two-week naval exercise, dubbed Dynamic Mongoose, brings dozens of vessels together, and comes amid concern about Russia's increasing aggression.

The intrusion occurred last month. Although defense analysts have said Russia is the likely culprit, Swedish authorities say it's "impossible" to say whose submarine it was.

Stockholm has a grainy photo of what it says shows "foreign underwater activity" in an incident eerily similar to the grounding of a Soviet submarine in the same waters in 1981.