By Joe Cash and Ryan Woo BEIJING (Reuters) -Authorities moved more than 45,000 people in earthquake-hit Tibet to shelters in a massive rescue operation near the foot of the Himalayas, as they wound down the search in a high-altitude environment where the odds of survival were always slim.

Thousands of rescuers were searching for survivors in freezing conditions Wednesday after a devastating earthquake in China's remote Tibet region killed at least 126 people.

The China Earthquake Networks Center measured the quake's magnitude as 6.8, while the U.S. Geological Survey reported it as 7.1.