Up to 1.3 million people in west China's Sichuan Province may have to evacuate to higher ground for fear of a major "quake lake" burst as a result of flooding and strong aftershocks.

On Friday Tan Li, Party Secretary of Mianyang City and chief of Mianyang City Quake Control and Relief Headquarters, issued an order to 1.3 million people living downstream from Tangjiashan, a deepening quake-induced lake. They must rehearse evacuation to higher ground demarcated by government departments in preparation for a worst-case scenario.

Currently, at least 190,000 people in at-risk areas downstream from the quake lake have been evacuated, after Tan's first order was issued yesterday.

The mass evacuation, dubbed a "drill" by local government officials, is said to make way for a possible flood discharging operation set for the weekend.

In accordance with a notice posted by the Tongkou Township Government of Mianyang City seen by Xinhua reporters at the site, starting 8 a.m. on Saturday till the warning is lifted, all people are banned from activities at a line below 36 meters -- a mark the level of the flood water might come up to when the quake lake fully opens.

The fear is that Tangjiashan Lake, formed by landslides that blocked a river known as the Jianjiang after the May 12 quake, is at risk of breaching its bank. This has worsened as heavy downpours started about 10 p.m. on Wednesday and lasted into Thursday around Tangjiashan, driving up the water level in the lake.

Tangjiashan, one of 35 such lakes, is inaccessible by road and can only be reached by foot or air.

By 4 p.m. on Thursday, the water level was 745.5 meters at its highest point before the debris blockage, about 22.78 meters from the lowest barrier.

Meanwhile, the seismological observatory in Sichuan Province is predicting that aftershocks will continue along the northern end of the Wenchuan-Beichuan-Qingchuan faultline in the coming days, with the most powerful being estimated to go around 6.5 in terms of magnitude.

(Xinhua News Agency, China.org.cn May 30, 2008)