The death toll shot up from the 410 given on Tuesday after rescue teams reached remote villages that could not be accessed earlier, Xinhua reported.

Priority has now shifted to getting resources to survivors.

"We will not rest until the last missing person is pulled from the rubble," said Yuan Zhengxiong , an information officer with Zhaotong city fire services. "However, what we are doing most now is helping to carry coffins into villages for victims to bury their loved ones and carry tents, food and water to those who have survived."

Behind the main street in Longtoushan - epicentre of the quake that struck on Sunday - are ruins where a four-level building was flattened into a single-storey structure.

Watch: Rescue scenes from Yunnan earthquake

Wang Ping , 40, moved to Longtoushan from Sichuan province 13 years ago and rented a flat there.

She was standing with a dozen rescuers on top of the ruins, waiting anxiously even though she knew there was no hope. Her electrician husband Li Gang and her 19-year-old elder son, a civil engineering student at Wuhan University, have been buried for over 72 hours.

"I was told to give up hope," said Wang, who has left her 12-year-old son behind and headed to the ruins at sunrise every day since the disaster struck and not returned home until sunset.

"They already found my husband. They could see his face but his upper body was crushed by three and a half storeys of rubble.

"He was sleeping that afternoon and my elder son was playing with a computer next to him. They still couldn't confirm where he was buried," Wang said.

Rescue workers were spraying disinfectant in every tent yesterday to prevent outbreaks of disease.

Watch: Chinese quake victim loses hope to find his child alive