"Not enough evidence to say collision caused Kursk disaster"

Vladimir Putin has indicated the Kursk catastrophe might be blamed on poor naval preparation for military exercises.

The Russian president's theory casts doubt on the theory favoured by Navy officers that the submarine sank after a collision.

Mr Putin also criticised the search-and-rescue effort after the Kursk's sinking.

He noted the preliminary investigation had uncovered a lack of preparation before the exercises.

"It should be admitted that, despite the large amount of work done, no objective evidence proving this theory (of collision) has been received up to now," Putin said after a briefing by Russia's top prosecutor on the government's investigation into the disaster.

He said it was too early to draw a final conclusion on what caused the Kursk, one of the most sophisticated submarines ever built, to plunge to the bottom of the Barents Sea during military exercises on August 12, 2000, killing all 118 crew members.

"The materials submitted by the investigation enable us to draw a rather definite conclusion on the quality of preparations for and organization of military exercises and the organisation of search-and-rescue operations," Putin said, according to a statement released by the presidential press service.

It did not include any elaboration.

Putin asked senior military and defence officials to develop proposals to radically improve the Navy's performance in general.

The Navy has declined over the past decade, a victim of the economic slide and legal chaos following the 1991 collapse of the Soviet Union. Government financing has dried up, equipment has been pilfered away or aged beyond repair, and ships are rusting at their moorings.