NGARI - Four tourists died and two are missing after a pleasure boat capsized on a lake in Southwest China's Tibet autonomous region Thursday, the local government said Saturday.

The boat was carrying 10 tourists and a crewman on a tour of Pangong Tso Lake in Ngari prefecture, said a statement from the local government.

It said they all fell into the water after the boat capsized, and five were rescued. The survivors were described as being in stable condition.

By Saturday, rescuers had retrieved four bodies and were still searching for the two missing.

The dead were believed to be tourists from Shanghai, according to the survivors.

A spokesman with the regional tourism administration said they had received no reports of the accident from any travel service. "We assume the tourists were traveling on their own."

Pangong Tso Lake, with an altitude of 4,242 meters, covers 600 square km. The eastern part of the lake, in Rutog county of Ngari, is the world's highest freshwater lake, and its western part is a saltwater lake straddling the China-India border.

The lake area is subject to strong winds for at least 300 days of the year.