Santiago, Chile ? Eight Israelis and Palestinians left Thursday on an expedition to climb an unnamed, unconquered mountain in Antarctica, vowing to show they can work together under difficult, dangerous conditions.

The two yachts carrying the six men and two women of the “Breaking the Ice” expedition sailed from Puerto Williams, a Chilean navy base 2,050 miles south of Santiago.

“I think we are setting a very good example on how different people can live and cooperate together,” expedition leader Heskel Nathanial said as the expedition sailed off in good weather.

Minutes before their departure, he received phone calls from former Israeli Prime Minister Shimon Peres and Palestinian leader Yasser Arafat, Nathaniel said. He said Arafat invited the group to visit him after their adventure.

The four Arabs and four Jews plan to climb a mountain near the Bruce Plateau in Antarctica after sailing for 600 miles in some of the world’s most treacherous waters.

The yachts are expected to take four days to sail from Puerto Williams to Antarctica, via the Drake Passage. Then, they will sail for another five days along the Antarctic coast to the area selected for the climbing.

Two of the Palestinians on the expedition spent time in Israeli prisons — one for attacking Israeli soldiers and another who was accused of terrorism. Two of the Israelis are former members of an elite commando unit.

The nonprofit group Extreme Peace Missions said it organized the 35-day expedition “out of a belief that overcoming physical obstacles by working together as a team toward shared goals can unite the Israelis and Palestinians.”

The expedition also is sponsored by Israel’s Peres Center for Peace and according to organizers has received support from Arafat, U.N. Secretary General Kofi Annan, the Dalai Lama and former Soviet leader Mikhail Gorbachev.