SYDNEY (AFP) - A complex international operation to free a Russian ship trapped in Antarctica ended on Wednesday when the vessel cleared the ice field, as officials released a United States icebreaker from the rescue.
The Russian-flagged Akademik Shokalskiy became stuck on December 24, triggering a rescue operation coordinated by Australian authorities which included French, Chinese, American and German agencies.
China's powerful icebreaker Xue Long raced to respond to the ship, which had been carrying 74 people including scientists, passengers and crew, but was unable to break through and became trapped itself.
The Australian Maritime Safety Authority (AMSA) confirmed Wednesday that the Akademik Shokalskiy and the Xue Long "have broken free from the ice in Antarctica and are no longer in need of assistance".
The United States Coast Guard icebreaker Polar Star, which had been en route to the stranded ships, was released from the rescue and will now continue on its original mission to McMurdo Sound.
"We are extremely pleased to learn that both the Xue Long and the Akademik Shokalskiy freed themselves from the ice," said US Coast Guard commander Vice Admiral Paul F. Zukunft.
"This case underscores the dynamic and harsh operating environment and the necessity for Polar Class Icebreakers in the Antarctic.
AMSA said the captain of the Russian ship Igor Kiselyov told officials on Tuesday that cracks had started to open in the ice around the trapped vessel and a short time later it began to make slow movements.
The ship quickly managed to clear the area containing the heaviest ice and had begun making slow progress north through lighter ice conditions, but it was about 12 hours before it had left the ice field behind. It is now heading to New Zealand.
The captain of the Chinese vessel had also managed to break free of the heaviest ice at about the same time "and is now making slow progress through lighter ice conditions" and in need of no assistance, it said.
The Xue Long, or Snow Dragon, had been trapped in the thick Antarctic floes since last Friday, one day after dramatically rescuing 52 scientists, passengers and journalists from the Shokalskiy using its helicopter.
The 52 were transferred to the Australian Antarctic programme's supply ship the Aurora Australis, which had also raced to the rescue but was unable to break through the ice to reach the Russian vessel.
In total five ships were involved in the search and rescue mission - Akademik Shokalskiy, the French vessel L'Astrolabe, Xue Long, Aurora Australis and USCGC Polar Star.
The national Antarctic programmes and other agencies of France, China, Australia, Germany and the US helped with "actual operational responses, contingency planning or the provision of specialist data", AMSA said.
"This was a great example of the multi-lateral cooperative nature of Antarctic operations," the authority's acting chief executive Mick Kinley said.