The strong earthquake that jolted southwestern China appears to have left deep physical scars on Jiuzhaigou, a network of mountain valleys prized as one of the country's few remaining areas of pristine natural beauty.

At last 19 people were killed when a 6.5-magnitude quake struck on Tuesday with its epicentre in Jiuzhaigou, which is famed for more than 140 lakes whose waters range from crystal-clear to turquoise, lying at the feet of forest-clad mountains.

But the quake triggered massive landslides that raked swathes of green forest from the mountainsides, scarring them with huge earth-coloured gashes, according to aerial footage shot by the official Xinhua news agency.

In some places, the landslides tumbled into the glassy waters, turning them a cloudy mud-brown, footage from the Chongqing Economic Times showed.

One of the park's most photographed locations -- Sparkling Lake -- appears to have suffered particular damage, with images showing how a strip of land between lake sections had collapsed due to the quake, draining a section of the lake nearly dry.

A statement issued by park authorities said the area was "severely damaged" and listed a number of other spots in the park that had suffered damage.

More than 30,000 visitors were in Jiuzhaigou at the time of the earthquake, according to authorities, and most of them were evacuated from the park Wednesday.

The sort of beauty on display at Jiuzhaigou is increasingly rare in China, whose natural environment has been devastated in decades of rapid economic growth that has triggered rampant development and made it one of the most polluted countries in the world.