SYDNEY (AFP) - A Chinese icebreaker has failed to break through thick ice to free a ship carrying scientists and tourists stranded off Antarctica, forcing Australian authorities to look at other rescue options on Saturday.
The Australian Maritime Safety Authority (AMSA), which is coordinating the rescue of the Russian passenger ship MV Akademik Shokalskiy, said the icebreaker came within six-and-a-half nautical miles (12.04 km )of the ship but had to stop.
"The Chinese vessel unfortunately encountered some heavy ice that it's not capable of breaking through," AMSA spokeswoman Andrea Hayward-Maher said.
"So unfortunately it won't be able to continue through to the Akademik Shokalskiy. It's making its way back." "The rescue... unfortunately has stalled."
The Russian ship, with 74 people on board, has been trapped in ice about 100 nautical miles (185) east of the French base Dumont d'Urville since Tuesday.
The Chinese vessel came tantalisingly close to the trapped ship, with those on board reporting they could see it in the distance, but was forced to turn back to open sea once it realised it could not break through.
"At the horizon in the east I can see the Chinese icebreaker that we were hoping was going to be here within hours cutting us a path out of this place but it just couldn't make it," science journalist Andrew Luck-Baker onboard the Russian ship told the BBC.
"It slowed down to about half a knot and has decided to go back to where the sea begins and wait for the arrival of an Australian icebreaker. The idea now is for the two of them to come together in parallel towards us, cutting a wider path."
Three vessels with icebreaking capability, including Australia's Antarctic resupply ship Aurora Australis and French vessel L'Astrolabe, were ordered to the area to attempt to rescue the vessel once the distress signal was sent.
But it is not yet clear whether the Aurora Australis, which has the highest icebreaking rating of the three and is not due in the area until late Sunday evening, will be able to go any further than the Chinese vessel, the Snow Dragon.
The French and Chinese ships are now awaiting further instructions from Australian authorities.
"They are standing by to respond if necessary," Hayward-Maher said, adding that AMSA's rescue coordination centre was in contact with all the vessels.
"It is working through the various options."
She said these could include whether authorities could use a helicopter onboard the Snow Dragon to bring the passengers to safety during the current favourable weather.
The ship is carrying scientists and tourists who are following the Antarctic path of explorer Sir Douglas Mawson a century ago.
They have been carrying out the same scientific experiments his team conducted during the 1911-1914 Australian Antarctic Expedition - the first large-scale Australian-led scientific expedition to the frozen continent.
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.
The group became stuck when unexpected weather forced their ship into heavy ice and since becoming stranded have sat through an intense blizzard which appears to have increased the build up of ice around them.
One of the scientists onboard, Chris Turney, said the team had been attempting to update the scientific records made by Mawson's group a century ago - records which he said have become crucial in charting signs of global warming.
They had planned to return to New Zealand by early January.