(CNN) -- Two ships broke free Tuesday from the Antarctic ice that had trapped them off the continent's coast.
Cracks in the ice allowed the Russian research ship Akademik Shokalskiy to escape the ice field where it had been stranded for two weeks, Australia's Maritime Safety Authority said.
The Chinese icebreaker Xue Long, which had gotten stuck in the ice during an attempt to extract the Russian ship, broke free about an hour later, officials said.
The Akademik Shokalskiy had been trapped in unusually deep ice since Christmas Eve with scientists, journalists, tourists and crew members on board. A helicopter ferried the ship's 52 passengers to an Australian icebreaker last week.
"We continue to sail northward, changing courses and speed. The speed is 7 knots," the Russian ship's captain, Igor Kiselev, told the ITAR-TASS official news agency Tuesday.
The captain reported that his ship is now headed to New Zealand, the maritime authority said.
The Xue Long will remain on its original mission in the Antarctic, China's state-run Xinhua news agency said.
A U.S. Coast Guard icebreaker had been dispatched to help free the stranded ships over the weekend, but they broke loose before it arrived.
Meanwhile, the international team of researchers who were flown off the stranded Russian ship are on board the Australian icebreaker Aurora Australis, which is ferrying them to Australia's Casey Station on Antarctica.