The death toll had climbed to 1,144 and another 417 remained missing as of 5 p.m. Friday, about two and a half days after a devastating earthquake shook a Tibetan area in northwest China's Qinghai Province.

Rescuers search for survivors at a collapsed building in Gyegu Town of Tibetan Autonomous Prefecture of Yushu, northwest China's Qinghai Province, April 15, 2010.  [Xinhua]

The 7.1-magnitude earthquake, which shook the Yushu County in the Tibetan Autonomous Prefecture of Yushu at 7:49 a.m. Wednesday, has left 11,744 people injured, including 1,192 serious cases, Xia Xueping, spokesman with the emergency rescue headquarters, told a press briefing late Friday.

Xia said the death toll rose markedly Friday because the expanding rescue forces recovered more bodies from the debris with the help of large rescue equipment.

In addition, the missing list climbed as the transient population in the business town were counted for the first time, he said.

A total of 1,179 serious cases had been transported by air and road to hospitals in Golmud and the provincial capital Xining in Qinghai and several other capitals in neighboring provinces.

Many people are still buried under the debris of collapsed houses in the hardest-hit Gyegu Town near the epicenter, the seat of the Yushu prefecture government and home to 100,000 people. It sits at about 4,000 meters above sea level.

More than 85 percent of houses in Gyegu, mostly made of mudbrick and wood, had collapsed.

Thousands of rescuers are fighting altitude sickness and chilly weather to race the time to reach the trapped by Saturday morning, the end of internationally accepted "72-hour golden chance" for the trapped to still survive.