Chinese authorities began evacuating earthquake relief workers from a flood-risk zone today, in a drill that put 1.3 million people on alert to quickly leave if an earthquake-spawned lake breached a dam.

More than one million people may have to evacuate dozens of villages in a Sichuan province valley if an earthquake-spawned lake threatens to burst and flood the region, an emergency official warned yesterday.

More than a million people may have to urgently evacuate a Chinese valley threatened with flooding from a lake created by the earthquake.

China struggled to keep roads open to provide a lifeline for quake survivors today while the government warned that rebuilding after the disaster would be “arduous”.

About 80,000 people have been evacuated downstream of an unstable earthquake-created dam threatening to collapse, while Chinese troops rushed to carve a trench to drain the water before it flooded the valley.

Chinese soldiers using massive earth-moving equipment prepared to blast away part of a landslide today to ease the flooding threat from a river blocked up by the huge earthquake.

Chinese quake rescuers struggled with flooded rivers and dams in danger of collapse threatening to add to the devastation today.