Search vessels in the South Atlantic have picked up noises on their sonar which could be coming from the crew of a submarine missing for days, Argentina's navy said Monday.

The noises were detected some 360 kilometers (225 miles) off the coast, "on the edge of the (Argentine) shelf where there is an average depth of 200 meters," Navy spokesman Enrique Balbi told reporters.

The position was in line with the path the submarine would have taken to reach the base in Mar del Plata as planned, he added