At the local hospitals, doctors also raced against time to save lives.

Yang Huyong, deputy director of the intensive care medicine department at the People's Hospital of Linxia, said they were treating over 100 patients, aged 2 years to 79 years, as of 5 pm on Tuesday. The hospital has over 100 ICU beds.

Nine surgeries have been performed, and there are more than 30 cases classified as severe or critical, Yang said, adding that the serious injuries included cranial trauma and fractures.

Currently, there are six medical teams comprising over 40 personnel providing support at the People's Hospital of Linxia, while nurses have been mobilized from other hospitals.

In addition to government efforts, people helped one another survive the ordeal.

At the Gaji Chunlei Primary School in Liugou township, 79 boarding students were escorted to the playground by their teachers as soon as the earthquake hit the area.

Zhang Shunshan, the school's vice-president, said the teachers lit charcoal fires and used quilts to keep the children warm through the small hours. "We later contacted the parents and helped the students get back home safely by 10 am," Zhang said.

Gansu's earthquake relief headquarters has started a level-two quake emergency response, local authorities said.

Wang Xiaoyu in Jishishan county, Gansu contributed to this story.