Rescue workers in China ’s mountainous Tibet region are racing to reach survivors trapped under the rubble as night temperatures drop far below freezing point following a powerful earthquake.

China has almost doubled its tally of injured in Tibet's deadly earthquake as rescuers widened a search on Friday for survivors in a remote county near the foothills of the Himalayas, despite dwindling hopes for survival.

Authorities moved more than 45,000 people in earthquake-hit Tibet to shelters in a massive rescue operation at the foot of the Himalayas as they wound down the search in a high-altitude environment where the odds of survival were always slim.