|Health officials have been disinfecting large areas of the quake zone [Reuters]|
Relief workers in southern China are becoming increasingly worried about the threat of disease to survivors of last month's massive earthquake.
More than 5 million people were left homeless by the quake which devastated a large area of Sichuan province, and health ministry officials are racing to provide adequate clean food, drinking water and shelter.
While officials say there has been no serious outbreak of disease so far, workers in protective suits have been spraying scores of collapsed buildings with disinfectant.
Meanwhile, with millions of survivors crammed into tent cities and other temporary shelters, medical workers say they have evacuated some 10,000 injured people to hospitals outside Sichuan province to ease the pressure on local medical resources.
According to the latest government data, more than 69,000 people are confirmed to have died in the magnitude 7.9 quake, while more than 18,000 remain listed as missing.
With recovery efforts continuing, Sichuan's mountainous terrain has posed huge challenges to relief teams.
Dozens of small towns remain largely cut off, with landslides blocking roads across the region.
On Monday thousands of soldiers scoured remote mountains in search of a military helicopter that crashed at the weekend while ferrying survivors from the quake zone.
On the same day it was announced that troops aiding the recovery effort had completed work on a channel to divert water from a lake formed after quake-triggered landslides blocked the Tongkou river.
About 200,000 survivors were evacuated after rising water levels threatened to flood surrounding areas.
Across the disaster zone many survivors have begun returning to their home towns, risking unstable buildings and other dangers to salvage what they can from their shattered homes.
|Angry parents say officials must be brought to |
account over poorly-built schools [EPA]
In the town of Yinhua Al Jazeera's David Hawkins found survivors ignoring official warnings to avoid the area due a leak of toxic ammonia from a destroyed fertilizer plant that led to the evacuation of about 40,000 people.
Nearly 300 people were killed and more than 1,000 were injured in the earthquake and our correspondent says local officials have promised to rebuild the town from scratch.
Hu Jintao, the Chinese president, has given an assurance that reconstruction of the devastated region will be completed within 3-5 years.
Elsewhere in the quake zone anger is growing over allegations of shoddy building work, particularly in schools where thousands of children were killed while attending class.
On Tuesday police dragged away more than 100 parents attending an improptu protest outside a courthouse in Dujiangyan, northeast of Sichuan's capital, Chengdu.
The parents are angry at reports that architects and contractors cut corners to increase their profit from building schools that did not conform to regulations.
Many of the protesters held pictures of their dead children and chanted slogans demanding those responsible for building the schools be held to account.