Severe Antarctic weather was slowing an Australian icebreaker's bid to reach a Russian ship trapped in ice since Christmas eve with 74 people onboard, the Australian maritime rescue agency said on Monday.
The Aurora Australis was currently about 11 nautical miles (20 kms) from the stranded Russian ship Akademik Shokalskiy, said the Australian Maritime Safety Authority (AMSA), which is co-ordinating the rescue.
"The area is currently experiencing snow showers, resulting in poor visibility. The Aurora Australis is travelling slowly due to the conditions to ensure the safety of all on board," AMSA said in a statement.
AMSA had earlier expected the Aurora Australis to arrive at the scene Sunday evening.
"It is unknown at this time if or when the Aurora Australis will arrive near the Akademik Shokalskiy due to weather and ice conditions," the agency said.
The Russian ship left New Zealand on Nov. 28 on a private expedition to commemorate the 100th anniversary of an Antarctic journey led by famed Australian explorer Douglas Mawson.
It is now trapped some 100 nautical miles (185 km) east of French Antarctic station Dumont D'Urville and about 1,500 nautical miles (2,800 km) nautical miles south of Australia's southern island state of Tasmania.
The Akademik Shokalskiy's 74 passengers include scientists and tourists, many of them Australian, and what the Russian Foreign Ministry said were 22 Russian crew members.
Chris Turney, an Australian professor who helped organise the voyage on the Russian ship, posted photos of passengers on board, including one of a passenger and a penguin.
"Set up tent on top deck. All well. Aurora making good progress. Waiting game!" Turney said on his twitter on Monday morning.
Ice that has trapped the ship appeared to be cracking up, raising hopes for a rescue, Turney said earlier.
The Australian icebreaker was one of the three vessels sent to try and free the Russian ship.
A Chinese icebreaker, the Snow Dragon, has been halted by thick ice within sight of the ice-bound ship, while another French-flagged ship was no longer involved in the rescue.
The Chinese Snow Dragon would remain on standby until the Aurora Australis reaches the Russian ship, AMSA said earlier.
The Snow Dragon has a helicopter on board that can be used to rescue passengers if the Aurora Australis can not break through the ice, the agency said.