U.S. and British rescue teams have arrived in Russia's Far East to try to save the crew of a submarine stranded at the bottom of the Pacific. Time is running out for the seven sailors, who have limited air supplies left.

The rescue operation has become international, with British and American teams having flown in to the Kamchatka Peninsula with experts and rescue equipment.

Hopes are now increasingly pinned on this outside help, though the Russians are continuing their own operation to rescue the sailors.

Russian Navy Rear Admiral Vladimir Pepelyaev said the sub was towed a short distance overnight. "As you know we moved it 100 meters towards the coast and we then marked the site with buoys," he said. "A special vessel is getting ready now to bring it to the surface."

The U.S. and British planes have both brought underwater rescue vehicles known as Scorpios. These unmanned mini-submarines aren't designed to rescue people.

But they are designed to cut through metal cables, and the hope is they can cut away the obstructions that will allow the submarine to float to the surface.

Still, it will take them several hours to reach the scene.

It's not clear how the submarine became stranded two days ago. Initial reports said it became entangled in fishing nets. But then officials said it hit underwater antenna, part of Russia's coastal monitoring system.

There have also been conflicting official accounts of how much oxygen the crew has left.

It's all prompted inevitable comparisons with the "Kursk" disaster of five years ago. Then, all 118 sailors on board that submarine died, and Russian authorities were widely criticized for waiting too long to call for international help.

This time, at least, the call for help came quickly. But the crew has at most 24 hours' air supply left.

PHOTO CAPTION

Russia is racing to save seven crewmen trapped in a submarine on the Pacific Ocean floor with dwindling oxygen, as the US sent remote-controlled vehicles to join the rescue effort Here a obtained form the US Navy 'Super Scorpio' unmanned, remotely-operated submersible. (AFP)