New Delhi, May 28 : Over 150,000 people were evacuated on Tuesday night after engineers warned that the earthquake-created dam near Beichuan had burst its banks.
They said they were digging a diversion channel to prevent flooding by waters of the Tangjiashan Lake near Beichuan County.
The China Daily quoted local authorities as saying that 158,000 people had been evacuated by midnight Tuesday in the event of the Tangjiashan L overflowing its banks.
According to contingency plans, up to 1.3 million people from 33 townships of Mianyang City could be relocated if the lake barrier collapsed entirely.
Premier Wen Jiabao told a meeting of the State Council quake relief headquarters Tuesday that handling the quake lakes is the "most pressing" task at present.
The water level in the Tangjiashan Lake has kept rising and the water diversion channel won't be effective till June 5, experts said Tuesday.
Tangjiashan lake was holding 130 million cu m of water - or the volume of water in about 50,000 Olympic-size swimming pools - said Liu Ning, chief engineer of the Ministry of Water Resources who was at the site to oversee the diversion work.
More than 600 engineers and soldiers were working non-stop at the lake site to dig the channel.
Cai Qihua, of the Yangtze River Water Resources Commission, said 26 excavators and bulldozers were being used around the clock, and added that the water is rising by nearly two metres a day and had reached only 23 m below the lowest part of the barrier Tuesday.
Many towns and villages downstream held evacuation drills Tuesday.
Compounding flood fears, two fresh aftershocks struck quake-hit areas Tuesday.
A 5.7-magnitude aftershock struck Ningqiang county of Shaanxi province Tuesday at 4:37 pm. It was also felt in the provincial capital of Xi'an.
Earlier, at 4:03 pm, a 5.4-magnitude aftershock hit Qingchuan County in Sichuan, which is very close to Ningqiang,
The two aftershocks were also felt in the Sichuan provincial capital Chengdu and parts of Chongqing and Gansu.
More than 60 people were injured and 420,000 houses in Qingchuan collapsed in the aftershocks.
Qingchuan was the epicenter of a 6.4-magnitude aftershock on Sunday afternoon, which was the strongest aftershock since May 12.
The death toll from the quake reached 67,183 by midday Tuesday, with 361,822 injured and 20,790 missing, according to the Information Office of the State Council.
More than 45.61 million people were affected in the deadly quake, and about 15 million have been displaced, according to the office.
By noon Tuesday, donations in cash and relief materials from home and abroad reached 32.7 billion yuan (4.7 billion dollars). So far, 9.4 billion yuan (1.35 billion dollars) has been forwarded to the quake-affected areas, the office said.
Meanwhile, 566,400 tents had been sent to quake-affected areas by noon Tuesday, according to the Ministry of Civil Affairs.