UDIAN, Yunnan, Aug. 5 -- Rescuers are risking their lives as they work to resume road traffic in the mountainous quake-ravaged areas of southwest China's Yunnan Province.

As difficult relief operations entered the second day, roads leading to Longtoushan Township, epicenter of Sunday's tremor, have become passable. But they may soon be blocked once more as rain-triggered landslides threaten transport routes, said a spokesman with the traffic bureau of Zhaotong City, which administers Longtoushan of Ludian County.

Traffic control has been imposed on a major life line linking Ludian's county seat and Longtoushan, prioritizing ambulances and vehicles carrying relief goods. By 7 p.m. Monday, Zhaotong had dispatched nearly 800 medics and over 130 ambulances to Longtoushan.

As of 8 p.m. Monday, the bureau had mobilized more than 5,700 workers, along with 800 diggers, loaders and trailers, to clean up roads following the 6.5-magnitude quake that has left at least 398 people dead.

The workers are repairing roads destroyed in the worst-hit Ludian and Qiaojia counties. However, their efforts have been hindered by continuous downpours, falling rocks and aftershocks, said the spokesman.

One major road linking Zhaotong and Qiaojia has seen 141 sections with a length of 2,277 km damaged. Workers are tasked with removing 25 million cubic meters of debris left by 2,251 cave-ins, he said.

In addition, rescuers have resumed electricity supply for three quarters of the more than 38,000 households in Zhaotong suffering a power cut following the disaster, according to the provincial grid company.