In this photo taken in March 2006 the Captain Khlebnikov icebreaker seen in the Russia's Pacific port of Vladivostok, about 6,400 km (4,000 miles) east of Moscow. MOSCOW (AP) — A Russian ship reached open water off Antarctica after struggling through a huge mass of sea ice for days, a Russian shipping company and a British travel agency said Friday.

The icebreaker Captain Khlebnikov, with 101 passengers on board, got stuck in the ice earlier this week near Snow Hill Island in the Weddell Sea. It took the ship five days to get out of the ice, Fareastern Shipping Co. spokeswoman Tatyana Kulikova said.

British-based Exodus Travels Ltd. also said the ship was in open water and is expected in the Argentine port of Ushuaia on Sunday, six days behind schedule.

The cruise was advertised as a unique opportunity to watch emperor penguins in their natural habitat. The Finnish-built icebreaker has been used as a cruise ship for several years and carries two helicopters.

Kulikova said Antarctic weather is unpredictable in the early spring. "It's impossible to avoid worsening ice conditions with rapidly changing weather," she said.

"There was nothing extraordinary in those conditions," she said, adding that the ship's captain has 20 years of experience.

Officials said the passengers never were in any danger.

"It's part of Antarctic tourism — we always warn passengers about possible delays," Vyacheslav Naganyuk, the head of icebreaker fleet at the Fareastern Shipping Company, said in a statement.

Exodus Travels has about 50 clients on the ship. In a statement, its managing director Peter Burrell thanked them for their good humor and said they had "risen to the occasion in embracing both the thrills and challenges" of polar travel.

Kulikova said the icebreaker is scheduled to make another Antarctic cruise in the fall.

Two-week tours aboard the Captain Khlebnikov to see emperor penguins range from $13,890 (€9,350) to $22,690 (€15,280) per person.