The fortnight-long Australian-led operation to rescue two ships trapped by pack ice at Commonwealth Bay in Antarctica is over, after the vessels freed themselves.
The Australian Maritime Safety Authority on Wednesday confirmed the Russian ship Akademik Shokalskiy and China's Xue Long broke free of the ice, and no longer needed help.
The breakthrough came after a wind change shifted the direction of ice drift and broke up the heavy pack ice on the coast of Antarctica due south of Hobart, according to reports in Russia media.
The US Coast Guard's heavy icebreaker Polar Star was released from its rescue mission by AMSA, and resumed its original annual mission to break in to the McMurdo base in the Ross Sea, AMSA said.
The Shokalskiy, whose 52 rescued passengers were transferred to the Australian ship Aurora Australis, advised AMSA that it was headed for Bluff, New Zealand, where it was due for another tourist cruise.
The Xue Long, whose helicopter was used to transfer the group, said it would continue its research mission in Antarctica.
AMSA said the overall effort involved five nations, including France's L'Astrolabe.
"This was a great example of the multi-lateral co-operative nature of Antarctic operations," said AMSA's acting chief executive, Mick Kinley.