Bad weather has added to the problems at the scene, with choppy seas and high winds reported to have worsened overnight on Monday. Explosion theory The Oscar-II class nuclear submarine, was damaged during naval exercises on Saturday or Sunday and sank to the seabed off the naval base of Severomorsk, near Murmansk. Jane's Fighting Ships Russian media have speculated about the possibility of a collision with a foreign submarine, but Admiral Kuroyedov said on Tuesday that the most likely explanation was an explosion in a torpedo compartment. US officials have said that two of their submarines and a surface vessel were in the area, but that none of them had been involved in a collision. One of the US submarines reported having heard an explosion at the site on Saturday, however it is unclear whether this was the sound of an incident on the Kursk, or just one of the many bombs and shells used in the exercises.
Russian officials say they have confirmed that the front of the submarine is badly damaged.
Oxygen Latest reports suggest that efforts to supply the vessel with oxygen and power were unsuccessful. A decision on how to mount a rescue operation is expected some time on Tuesday. The United States, France and the UK have offered to assist in the operation, but Russian naval authorities say they have all the facilities they need. Navy officials said the submarine was not carrying any nuclear weapons, and no radiation leaks have been reported. The craft was reported to be listing at about 60 degrees to starboard.