A U.S. Coast Guard heavy icebreaker left Australia for Antarctica on Sunday to rescue more than 120 crew members aboard two icebreakers trapped in pack ice near the frozen continent's eastern edge, officials said, according to AP. The 122-meter (399-foot) cutter, the Polar Star, is responding to a Jan. 3 request from Australia, Russia and China to assist the Russian and Chinese ships because "there is sufficient concern that the vessels may not be able to free themselves from the ice," the Coast Guard said in a statement. The Russian research ship Akademik Shokalskiy has been trapped in ice-clogged Commonwealth Bay since last week, while the Chinese ship which came to its rescue, Xue Long or Snow Dragon in Chinese, reported on Friday it too had become stuck nearby. A day earlier, the Chinese ship's helicopter had retrieved from the Russian ship 52 scientists, journalists and tourists who are now on their way home aboard an Australian icebreaker, Aurora Australis. Authorities say the 101 crew aboard the Chinese ship and 22 aboard the Russian ship were well provisioned and in no immediate danger.