The May 12 earthquake seriously damaged local infrastructure, especially roads and telecommunications facilities, he said. "This added up the difficulties for rescue work in the early stage. Not mentioning foreign rescuers, even domestic ones could not reach the sites at the earliest time."

Many roads were blocked and inaccessible to vehicles. "It would take more than 10 hours to cover a distance that took two or three hours before the quake. And there were frequent aftershocks."

Members of a rescue team from Singapore search for survivors in the quake-hit Hongbai Town of Shifang City in southwest China's Sichuan Province, May 17, 2008. The team of 55 members from Singapore started their rescue mission in the serious devastated Hongbai Town on Saturday.(Xinhua/Jiang Fan) 

According to the Ministry of Civil Affairs, four rescue teams from Japan, Russia, South Korea and Singapore participated in the quake rescue task.

Nine medical teams with 223 members from countries including Britain, Japan, Russia, Italy, France, Cuba, Indonesia, Pakistan and Germany were working in quake-hit Sichuan and Gansu provinces. They had treated more than 6,400 patients.

According to the Red Cross Society of China (RCSC), the International Federation of Red Cross and Red Crescent Societies will send four emergency response units to China's quake areas.