More than 400 people trapped by rubble in earthquake-stricken Tibet have been rescued, Chinese officials said, with an unknown number still unaccounted for in freezing weather a day after a strong tremor rocked the Himalayan foothills.

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.

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.