Andrew Peacock/Agence France-Presse — Getty Images

A helicopter from the nearby Chinese icebreaker Xue Long arrived to pick up the first batch of passengers from the stranded Russian ship Akademik Shokalskiy.

LONDON — A helicopter from a Chinese ice-breaking vessel began a rescue on Thursday of 52 passengers trapped aboard an icebound research ship in Antarctica, landing next to the ship on ice that had been trampled into a makeshift landing zone, according to a passenger and a leader of the scientists on board.

The helicopter from a Chinese icebreaker, the Xue Long, or Snow Dragon, was to ferry the 52 passengers — scientists, tourists and several journalists — a dozen at a time, ending more than a week of drama in which ice held the MV Akademik Shokalskiy research ship firmly in place and prevented other vessels from approaching.

Chris Turney, a leader of the research expedition and a professor of climate change at the University of New South Wales in Australia, said in a message on Twitter that the "Chinese helicopter has arrived the Shokalskiy. It's 100% we're off! A huge thanks to all."

Andrew Luck-Baker, a BBC reporter on board the vessel, said the rescue was underway and would likely take several hours. According to news reports, passengers would be ferried from the Xue Long to an Australian icebreaker, the Aurora Australis, some 2.5 miles further away while the 22 crew members stayed with the icebound Akademik Shokalskiy.

The passengers were expected to make landfall on the Australian island state of Tasmania in mid-January.

The 233-foot Russian research ship had been lodged in the ice since Dec. 24, when powerful winds encircled it with pack ice near Cape de la Motte, about 1,700 miles south of Hobart, Tasmania.

The ship had set sail from Bluff, New Zealand, on Dec. 8, embarking on a planned monthlong voyage known as the Australasian Antarctic Expedition to study changes to the environment of East Antarctica since an Australian geologist, Douglas Mawson, surveyed the region a century ago.

Efforts to rescue the passengers began when the Aurora Australis was diverted from a resupply operation at an Australian Antarctic base. But the ship was unable to break through and risked getting stuck itself, according to Australian maritime authorities.

The Xue Long failed in a similar attempt on Saturday but remained in the area. The Chinese ship is about two months into a five-month Antarctic expedition.

According to a posting on the expedition website by Dr. Turney on Dec. 31, the nearest open water from the ship was 16 nautical miles away across the ice. Neither the research ship nor its passengers and crew were in immediate danger, maritime authorities said.