JIANGYOU, China - Nearly 160,000 people were evacuated downstream from an unstable earthquake-created dam threatening to collapse, while troops rushed to carve a trench to drain the water before it floods a valley.
The threat of flooding from dozens of lakes swelling behind walls of mud and rubble that have plugged narrow valleys in parts of the disaster zone is a new worry for millions of survivors.
Dozens of villages were emptied, the official China Daily said Wednesday. It quoted Premier Wen Jiabao as telling a meeting of the State Council, China's Cabinet, that handling the danger from the swelling lakes was the "most pressing task" right now.
The newspaper said 158,000 had been evacuated in case the newly formed Tangjiashan lake bursts before soldiers and engineers can drain it.
Troops used explosives Tuesday to blow up tree stumps that were hampering heavy-duty excavators at the lake near the town of Beichuan, the official Xinhua News Agency reported.
The magnitude-7.9 quake that struck Sichuan province May 12 sent a mass of dirt and rocks tumbling in the valley about 2 miles (3.2 kilometers) above the town in a spot not accessible by roads, plugging a river that is now forming the lake.
Some of the evacuated people were sent to camps near Jiangyou, where government-issued tents were pitched on a hillside overlooking the river.
Elsewhere in the region, workers also used explosives to level some buildings that were left teetering by the quake