The first team of more than 180 medics organized by national health authorities was sent to earthquake-affected areas on Saturday. Most came from Sichuan, Chongqing and Shaanxi, and all had experience in emergency response.

By Saturday afternoon, more than 650 people injured had been treated at tent clinics. The most seriously injured were rushed to hospitals in Ya'an and Chengdu for treatment, according to provincial health authorities.

The Chinese National Health and Family Planning Commission has organized a panel of experts in medical treatment and epidemic prevention to manage medical relief efforts across the country.

At this stage, surgeons, pediatricians and anesthesiologists are most needed.

Feng Zijian, director of the health emergency center of the Chinese Center for Disease Control and Prevention, said that due to the high temperature there, epidemic prevention work is also critical.

More than 200 people on 15 medical teams dispatched by the Sichuan provincial health administration were already at work in Lushan county on Saturday. Additional teams with emergency-response experience are being organized, according to the commission.

The State Administration of Traditional Chinese Medicine has organized more than 50 medical experts and sent out nine ambulances to the earthquake-hit areas on Saturday, the administration said on Saturday.

Another three medical teams with professors and doctors are on stand-by and will be sent to the quake-hit areas if necessary, the administration said.

Francis Markus, a spokesman for the International Federation of Red Cross and Red Crescent Societies (East Asia), said: "It's still the early stage of the disaster relief as it takes time to reach some of the mountainous areas affected".

He said urgent tasks now include rescuing people still buried in debris, setting up shelters to protect the residents from aftershocks, ensuring supplies of clean water and safe food, and treating the injured.

Hou Shike, leader of the national medical response team, said it was important for relief workers to get to affected areas quickly.

"Professional and proper on-site medical treatment is crucial to save lives in natural disasters like the earthquake," he said.

The Red Cross Society of China is also working closely with the emergency effort.

The society set up an earthquake relief team headed by executive Vice-President Zhao Baige. Its main focus is to get supplies for medical treatment and daily necessities to those in need.

By noon on Saturday, the society had sent disaster-relief materials including 1700 tents and 5400 emergency response kits, food and water to Ya'an. Meanwhile, well-trained disaster relief and rescue teams under the Red Cross were also heading to the quake-hit areas.

Outside China, "the International Red Cross is ready to support upon request from the Chinese Red Cross," said Francis Markus.

Kevin Xia, information officer of the International Federation of Red Cross and Red Crescent Societies (East Asia), told China Daily on Saturday afternoon that he was on the way to the epicenter in Lushan county.

Due to bad traffic and road conditions, "our car could move only 30 to 40 km per hour," he said. Cave-ins are happening frequently on some parts of the mountain road to Lushan, he said.

"I can see cracks on the buildings along the way, but few had collapsed," he noted.

Xia said he was on the scene to assess the disaster. "That helps us to understand the needs and guide future relief work," he said.