Thousands flee over China 'quake lake' fears

• Story Highlights
• NEW: Thousands of people evacuated over fears newly-formed lake will burst
  
• Engineers are working to create a spillway to relieve pressure on the new dam
  
• This month's magnitude-7.9 earthquake created 35 so-called quake lakes
  
• NEW: Official death toll from the original quake has now risen to 67,183
  
  

BEIJING, China (CNN) -- Authorities evacuated thousands of people in southwestern China's Sichuan province Tuesday as engineers prepared to blast a potentially dangerous lake created by landslides from this month's earthquake.

About 158,000 people were expected to have fled their homes downstream by midnight (1600 GMT, 1200 ET), China's Xinhua news agency reported. The evacuations are taking place in nearly 170 communities.

That number could increase to more than a million if authorities fear the entire dam -- caused by the debris -- is about to give way.

"It's better for them to complain about the trouble that the evacuation would bring than to shed tears after the possible danger," said Liu Ning of the Ministry of Water Resources.

Tangjiashan Lake was formed when landslides from the May 12 earthquake blocked a section of the Jianhe River. It is holding back 130 million cubic meters (170 million cubic yards) of water, according to Liu.

Engineers are working to create a spillway to relieve pressure, but they do not have a lot of time to work with, Xinhua reported. http://i.l.cnn.net/cnn/.element/img/2.0/mosaic/tabs/video.gifflee over china 'quake lake' fears" />Watch soldiers dig out landslides as blasts ring out »

The river has been rising at a rate of about two meters (six feet) a day and is within 26 meters (85 feet) of the top.

Thirty-five of these so-called quake lakes were created by this month's 7.9-magnitude earthquake and 28 of them are "at risk," according to the Ministry of Water Resources.

The official death toll from the quake rose to 67,183 on Tuesday, an increase of more than 2,000, with about 21,000 missing. The total number of dead has been increasing on a daily basis.

The efforts to drain the lake came as two more aftershocks rattled the region Tuesday afternoon. http://i.l.cnn.net/cnn/.element/img/2.0/mosaic/tabs/video.gifflee over china 'quake lake' fears" />Watch a wedding photographer's shots of the initial quake's impact »

Striking about half an hour apart, the moderate earthquakes registered at magnitude 5.2 and 5.7, according to the U.S. Geological Survey.

As of late Monday, more than a thousand engineers and soldiers were working at the site in Beichuan county.

The Chinese military flew in about 80 pieces of heavy equipment, because there are no roads into the area. Engineers have 10 tons of dynamite on hand to clear rock and soil for the planned spillway.

The government estimates that 45 million people, mostly in Sichuan province, were affected by the earthquake and that 5 million were left homeless. http://i.l.cnn.net/cnn/.element/img/2.0/mosaic/tabs/video.gifflee over china 'quake lake' fears" />Watch how a survivor reacted to a collapsing mountain »

Meanwhile, Chinese officials on Monday emphasized that the country's one-child policy allows families with a child killed, severely injured or disabled to have another baby.

A strong aftershock on Sunday killed at least eight people, injured about 1,000 others and destroyed more than 70,000 homes in Sichuan, Gansu and Shaanxi provinces.

The worst damage occurred in Sichuan, which has experienced thousands of aftershocks over the past two weeks, but Sunday's -- which the U.S. Geological Survey measured at a magnitude-6.0 -- was the strongest since a magnitude-5.8 tremor shook the region a day after the initial quake.

Shaanxi experienced the highest death toll as a result of the aftershock, with four people losing their lives. One each died in Sichuan and Gansu.

The aftershock damaged more than 200,000 other homes, according to state media. It also damaged another dam, cutting off several more roads in the region.