LUDIAN, Yunnan, Aug. 8 -- With two more bodies retrieved, the death toll from the Yunnan earthquake rose to 617 as of Friday afternoon.

A barrier lake near the border of Ludian and Qiaojia, formed when landslides blocked the Niulan River, still poses a big risk. The water level is still rising.

It is difficult to transport large machinery to the site, but the clear-up operation began on Tuesday with three excavators arriving on the scene.

"Aftershocks cause frequent landslides, which have affected our work. We have to use dynamite to blow up blockages," said rescuer Fan Tianyin.

Two hydropower stations on the lower reaches have discharged nearly 100 million cubic meters of water and one reservoir on the upper reaches has intercepted more than 10 million cubic meters.

The lake has already flooded several villages and forced 8,172 residents to evacuate.

Good news is that all but three roads in quake zone had reopened as of 4 p.m. on Friday.

The quake occurred at 4:30 p.m. Sunday with its epicenter at Longtoushan Township.