China today struggled to bury its dead and help tens of thousands of injured and homeless as a powerful aftershock brought new havoc four days after an earthquake thought to have killed more than 50,000.
The aftershock, measuring 5.9 on the Richter scale, hit Lixian, to the west of the epicentre in Wenchuan, cutting off newly repaired roads and telecommunications.
China put the death toll at just over 22,000 on Friday but has said it expects it to exceed 50,000. About 4.8 million people have lost their homes.
Thousands of men, women and children were heading by foot for Mianyang, a city near the epicentre, saying they were abandoning their ruined villages for good.
Anger has focused on the state of school buildings, many of which crumpled in Monday's 7.9 magnitude quake, burying thousands of children and prompting the Housing Ministry to order an investigation.
President Hu Jintao flew to the battered province of Sichuan, and Premier Wen Jiabao said the quake damage could exceed the devastating 1976 tremor in the northeastern city of Tangshan that killed up to 300,000 people.
Mr Wen called on officials to ensure social stability as frustration and exhaustion grew among survivors, many of whom lost everything and were living in tents or in the open air.
President Hu and Premier Wen stressed that searching for and rescuing survivors remained the top priority. "We cannot talk about giving up too easily," Wen said. "Life should go on. I believe people in the quake area can definitely build their hometown even better with their own hands. That is also the biggest consolation for the dead."
The country is on precautionary alert against possible radiation leaks, according to government website. The disaster area is home to China's chief nuclear weapons research lab in Mianyang, as well as several secretive atomic sites, but no nuclear power stations.
China has mobilised 130,000 army and paramilitary troops to the disaster area, but with buckled and blocked roads, supplies and rescuers have struggled to reach the worst-hit areas.
The first foreign rescue team, a group of about 60 people from Japan, reached Sichuan today, and rescue teams from Russia, Taiwan, South Korea and Singapore have also arrived in the province.
Despite the growing death toll, rescuers were still finding survivors among the rubble. A 50-year-old worker was rescued from a collapsed fertiliser plant after being trapped for about 100 hours, a witness said.
There were concerns about epidemics if the dead were not soon buried or cremated, however.
Hundreds of damaged dams have also raised fears of collapse or flooding that could inundate towns and cities that are already struggling to recover from the quake.
China has asked the United States for satellite images to help locate victims and identify damaged infrastructure