Nearly 100 hours after the 7.8-magnitude earthquake, tired rescuers could still detect signs of life in the rubble of Mianzhu City's Hanwang Town, Sichuan Province, according to sources with the Chinese national rescue team on Friday.

"There is a good chance that we can rescue the buried," said a team member.

Rescue work came to a critical stage yesterday as survival chances for those trapped were growing slim after the first 72 hours. But a rescue team member said: "Giving up is excluded from our dictionary."

By 6pm yesterday, rescuers from the eastern Jiangsu Province found a survivor under the debris of a flattened chemical fertilizer plant in Shifang City.

The government has vowed not to abandon the search for survivors. "Where there is a ray of hope, we will spare no efforts to save the trapped," said Premier Wen Jiabao during his tour of the quake-hit areas.

President Hu Jintao flew into Sichuan yesterday and called for relief efforts to be stepped up, saying rescue work has entered its "most crucial phase."

A 23-year-old nurse was rescued at 2:23pm yesterday from a collapsed town hospital in Beichuan, four days after the earthquake that could have claimed more than 50,000 lives.

Yesterday rescuers pulled a student from debris at Beichuan Middle School, 80 hours after the earthquake hit Beichuan County.

Also yesterday, a 104-year-old woman in Sichuan's Maoxian County was rescued. Rescuers trekked six hours to reach her home in mountainous Gaochuan Town and carried her to safety.

The death toll in Sichuan had exceeded 21,500 while 14,000 others remained buried as of 4 pm yesterday, the government said.

(Xinhua News Agency May 17, 2008)