Updated

The death toll in southern China's earthquake rose to 589 on Wednesday as search and rescue teams worked to clear debris from isolated mountain communities struck by the disaster.

The Yunnan provincial government said more than 2,400 people have been injured in Sunday's 6.1 magnitude quake in the mountainous Yunnan farming region of Ludian county -- the country's deadliest in four years.

Thousands of troops and hundreds of volunteers have rushed to the site to dig out possible survivors from the debris, but landslides and heavy rains have complicated rescue efforts.

The quake struck an area of steep hills and narrow roads that are not well suited to all the traffic of the massive relief effort.

Roads into the hardest-hit town of Longtou were clogged Wednesday with rescue vehicles, ambulances and military jeeps along with residents and volunteers on foot.

The region is prone to earthquakes. In 1970, a magnitude-7.7 earthquake in Yunnan killed at least 15,000 people. In September 2012, a series of quakes killed 81 people.

In May 2008, a powerful quake in Sichuan province left nearly 90,000 people dead.