Prevention of secondary disasters, such as landslides and mud-rock flows, amid rain storms and frequent aftershocks following the May 12 earthquake was an "urgent task", said the quake relief headquarters of China's State Council on Monday.

"New geological disasters can happen at any time due to the long-lasting aftershocks and much stronger precipitation as the country's rivers enter the flooding season," the headquarters warned after a meeting presided by Premier Wen Jiabao.

The quake zone and the rain-lashed southern regions are the focuses of the prevention work, according to the meeting.

Work must be sped up to remove the dangers of quake-formed lakes, quake-damaged dams and hydropower plants as well as dikes of major rivers, the headquarters said.

The headquarters urged local governments and related departments to strengthen monitoring and alarms of rains, floods and aftershocks, and told quake-hit regions to base their recovery plans on geological hazard assessment.

Up to 50,000 residents were asked last week to move from highly-dangerous terrain in Wenchuan, epicenter of the May 12 earthquake, to shelters built on open and solid ground before June 30 to avoid secondary disasters.

As of Monday noon, 12,437 aftershocks had been detected since the 8.0-magnitude quake struck southwest Sichuan Province, official figures show.

By Sunday, at least 57 people had been killed and 1.27 million people relocated as rainstorms and floods ravaged nine provinces and region in south China.

(Xinhua News Agency June 17, 2008)