All vacations and days off were cancelled and all doctors are asked to work the day shift, with half also having to stay at the hospital for the night. Those returning home were on call in case of emergencies.

'Half of us have not gone home since Wednesday. We are fine, but we're starting to feel tired,' Han said. 'At this moment, the biggest challenge is lack of sleep.'

Wang Kai , Han's deputy, was a member of the first medical relief mission to fly into Yushu on Wednesday. He said that hospitals in Xining would face more pressure because the top priority for injured survivors was to transfer them to places with enough medical support.

'There is no power, no water, no surgical instruments in Yushu. We could only try to stabilise their condition by doing some simple treatment,' Wang said, adding that the dusty conditions made it hard to treat fractures because of the risk of infection.

He said that following Premier Wen Jiabao's visit to the epicentre, the health and other departments were trying to send injured people, especially those with severe injuries, to hospitals across the country because there was no hope for them if they waited in Yushu.

But he believed that hospitals in Qinghai would have to deal with most of the survivors.

'Most of them are Tibetans. They will have language, food and other problems if they go to other provinces,' he said.

The hospital's orthopaedic department has received the most quake survivors - more than 100.

Han said the department's 162 beds were almost full before Wednesday and they had to treat the newcomers in beds in corridors, which were also full by yesterday.

The department's biggest meeting room was cleared yesterday afternoon and nurses prepared 10 beds for survivors with less serious injuries.

To be ready for more survivors, the hospital has created a ward with space for 50 beds. Shen Xiaozhong , Han's other deputy, who is in charge of the new ward, said he was worried the department might become overloaded.

The Ministry of Health said medical institutions in Qinghai had received 631 survivors by yesterday morning. Seventy per cent of all the injured had been transferred from Yushu to other places in Qinghai and other provinces, including Shaanxi , Gansu and Sichuan .

Xinhua reported that 11,744 people were injured in the quake, 1,192 severely. About 4,200 had been discharged from hospitals.

Yin Dong , a doctor from Guangdong People's Hospital who arrived in Xining as part of a team of 27 Guangdong doctors, said that if survivors could not be treated in Yushu or sent to other places in time, many might lose their lives.

Han agreed. He said the hospital had sent more than 40 doctors and nurses, including Wang, to Yushu in the past three days but there was no chance they could operate successfully in the quake-hit area.

'They do not have tents and the necessary surgical instruments up there, without which our experienced doctors could ... not do basic operations for those severely injured,' he said. 'It feels like we're soldiers who have no guns at the front.'