As Russia and the wider world looked on anxiously, the last hope of saving any of the 118 crew trapped on board the Kursk submarine rested solely on a British high-tech mini-sub being rushed to the Barents Sea accident site Saturday.

But most observers said Friday that even if the British sub did manage to dock with the Kursk — which has been lying on the ocean floor for seven days — it would probably be too late. The Russian Navy had said that the crew would run out of oxygen Friday, but Navy officials later said the air supply could perhaps last into next week.

The Kursk is lying 106 meters (350 feet) below the surface of the Arctic Barents Sea at an angle of 20 degrees and is said to be sinking into the mud.

The Russian Navy continued to attempt to dock with the submarine through Thursday evening and Friday morning, with RTR State Television's Arkady Mamontov — reporting from a ship above the accident site — saying that a Russian rescue capsule had docked with the Kursk late Thursday evening.

But, according to Mamontov, the capsule was forced to disengage when it did not have sufficient electricity reserves to decompress the chamber between itself and the Kursk. It was also reported that the hatch on the Kursk was damaged.

Mamontov also cited Russian officials as saying that debris had been discovered around the submarine, which they implied was evidence that the disaster was the result of a collision rather than an internal explosion.

Although public faith in the military top brass has evaporated over the past week – due to its handling of the crisis – a report that the submarine's periscope was still raised lent credence to the theory that the Kursk was preparing to surface when it collided with something.

But Western news agencies, citing unidentified U.S. intelligence sources, said American vessels in the Barents Sea area had detected two explosions on Aug. 12, the day the accident happened, and the second was a major one. Analysts said a possible scenario was that a torpedo in the Kursk's forward torpedo compartment had exploded, triggering a much bigger explosion in an adjoining torpedo section.

The Kursk can carry up to 28 torpedoes and anti-submarine missiles, each with warheads weighing up to 450 kilograms (1,000 pounds). Though the vessel is designed to withstand a single enemy hit, a blast of a few torpedo warheads would cause catastrophic damage.

Video footage of the submarine taken by an unmanned Navy vessel showed massive damage to the bow and conning tower of the submarine. Russian officials said the Kursk's crew probably had no time to escape "a catastrophe that developed at lightning speed."

The vessel's commanding officers would normally be in a section just below the conning tower, and experts said their chances of survival were minimal. Other senior naval personnel were also on board the Kursk to observe the war games the submarine was engaged in.

Deputy Prime Minister Ilya Klebanov, the head of the government commission reviewing the rescue effort, said there was a "terrifying hole" on the starboard side of the submarine, Russian news agencies reported.

"A rather big part of the crew was in the part of the boat that was hit by the catastrophe that developed at lightning speed," Klebanov said Thursday. He said there had been no sounds within the Kursk for a long time.

It had been reported that a tapping sound signaling "SOS" had been heard from the submarine until Tuesday, though there were conflicting statements on sounds from the submarine, with some officials saying nothing had been heard from the Kursk since it sank last Saturday.

All eyes and hopes Friday were on the British submarine, the LR5, which is described as something like an "underwater helicopter." It is built of glass-reinforced plastic and steel to withstand the massive pressures encountered at such depths. But the LR5 has only been used in exercises, and its capacity in real conditions remains unknown.

The plan is for three Russians, including a doctor, to join the LR5's crew in the first attempt to open an escape hatch on the Kursk's stern. The LR5 will also carry oxygen, food and electric power.

Reaction by the Russian media to the handling of the tragedy by the government and military has been scathing.

The Komsomolsky Pravda newspaper published a special issue Friday with a list of the men aboard the Kursk, claiming it had paid Navy officials 18,000 rubles ($650) for the names. The navy has not officially said who is on board, fueling further criticism of the military's slow, confused and often contradictory response to the disaster.

President Vladimir Putin has also come in for the harshest criticism of his career over the affair.

"Those dying in the Barents Sea did not merit our statesmen interrupting their summer holidays." Izvestia wrote, referring to Putin choosing to go on vacation in Sochi even after news of the tragedy broke.

Putin, who announced Friday he was cutting short a meeting in Yalta with CIS leaders to return to Moscow, responded to the criticism, telling Interfax that when he heard of the accident his initial reaction was to travel to the scene.

"But I stopped myself from doing so, and I think I did the right thing," Putin said. "The arrival of non-specialists and top-ranking officials at the emergency area does more harm than good."

"As soon as communication with the submarine was disrupted on Aug. 12, it was clear that there was an emergency. A rescue operation began immediately," Putin added. "The other thing is that information on [the accident] was released to media later. You can criticize [Navy officials] for that or you can try to understand that they had to figure out what was going on before issuing an official statement."