Officials say a Chinese icebreaker trying to a reach a Russian strip trapped in Antarctic ice has been blocked by heavy sea ice.
The Chinese "Snow Dragon" is the third icebreaker that has been dispatched to free the Russian ship "MV Akademik Shokalsky," which became stranded on December 24 while on a research expedition.
A French ship has also been blocked by the thick ice.
An Australian ship is expected to arrive in the area on December 29 for an attempt to break through.
The ship's 74 passengers include scientists and tourists, many of them Australian.
The Russian Foreign Ministry said there were 22 Russian crew members.
The expedition has been seeking to follow the Antarctic path of Australian explorer Sir Douglas Mawson, who mounted an expedition a century ago.
Based on reporting by Reuters, AFP, and AP