Bad weather on Monday forced back an Australian icebreaker struggling to reach a scientific expedition ship stranded off Antarctica, while snow and winds have prevented a helicopter rescue, authorities said.
The Aurora Australis made it to within 10 nautical miles of the MV Akademik Shokalskiy, which is stuck in an ice field, before retreating in the face of freezing winds and snow showers.
"Adverse weather conditions have resulted in the Australian Antarctic Division vessel Aurora Australis moving back into open water this afternoon," the Australian Maritime Safety Authority said.
"The area where the MV Akademik Shokalskiy is beset by ice is currently experiencing winds of up to 30 knots and snow showers.
"These weather conditions have resulted in poor visibility and made it difficult and unsafe for the Aurora Australis to continue today's attempt to assist the MV Akademik Shokalskiy."
The authority said further rescue attempts could be made by the Australian vessel once the weather improves and it was now in open waters about 18 nautical miles east of the trapped Russian ship.
Australia's rescue coordination centre is in regular contact with the stranded ship, which is carrying 74 people -- including scientists, tourists and crew -- and has been stationary since December 24.
Its passengers, who had been following in the Antarctic footsteps of Australian Sir Douglas Mawson and his 1911-1914 expedition, remain safe and well on their well-provisioned vessel, AMSA said.
Three icebreakers including the Aurora Australis were called to help free the Russian vessel, which endured a fierce blizzard that appears to have increased the build-up of the surrounding ice.
But an attempt by one of these, a Chinese-flagged vessel, was unable to break through the ice and had to retreat while the third vessel was released from the rescue, concentrating hopes on the Australian icebreaker.
Authorities had hoped that a helicopter on board the Chinese flagged vessel that remains in the area would be able to evacuate the passengers if the Aurora Australis was unsuccessful.
But AMSA said Monday it was also "unsafe to attempt to launch the helicopter from the Chinese vessel" given the weather.
Australian authorities took over the search and rescue operation on Christmas Day after Britain's Falmouth Maritime Rescue Coordination Centre received a distress message via satellite from the Akademik Shokalskiy.
"Obviously we want everyone to be safe, so we're just playing it by ear and leaving it up to the master to progress as he sees fit," AMSA spokeswoman Lisa Martin told the broadcaster ABC earlier Monday.
Chris Turney, one of the leaders of the scientific expedition, said there had been high winds early Monday, meaning communications had been limited.
"Set up tent on top deck. All well. Aurora making good progress. Waiting game," he tweeted.
Turney had earlier tweeted that cracks were developing in the ice around the bow of the ship, something he hoped would help free the vessel.
The team onboard has been carrying out the same scientific experiments Mawson's group conducted during the 1911-1914 expedition in the hope they could help in climate change research.
Several members of the team have already battled sea ice to reach the historic Mawson's Huts -- built and occupied by the 1911-1914 expedition -- which have been isolated for years by a giant iceberg.