Officers and soldiers of the Chinese People's Liberation Army work in a rescue operation in the rubbles of destroyed houses in Yushu County, northwest China's Qinghai Province, April 14, 2010. (Xinhua/Li Shuisheng)

The town is located in a remote area in Qinghai and the quake and ensuing landslides have damaged roads, causing great difficulties for resucers and, especially, machines from outside to enter the region.

Rescuers had to dig with bare hands or iron sticks Wednesday, looking forward for the arrival of digging machines, said a rescuer surnamed Wang, who was working at a collapsed hostel.

The searching operation became even harder at night without lighting facilities, he said.

In addition, rescuers may easily get exhausted working at a place with an altitude of above 4,000 meters.

Thoudsands of rescuers and medical staff are rushing to Yushu from many regions of China, bringing machines, disaster-relief materials and medicines to the quake-hit town. Governments, organizations, enterprises and individuals are offering donations of money and materials to the region.

The quake, which struck Wednesday morning and was followed by a string of aftershocks, has left at least 400 people dead and 10,000 others injured. As many people are still buried under the rubble, the casualties may increase as rescue operations get intensified.