China on Thursday ramped up its response to an earthquake that killed 20 people and injured hundreds, sending supplies and personnel into the mountainous zone as rescuers fanned out to search for more victims.

AFP journalists in Jiuzhaigou, a popular tourist destination near the epicentre of Tuesday night's 6.5-magnitude quake, saw dozens of relief and military trucks rolling through the remote corner of Sichuan province.

Locals took refuge in blue relief tents in several makeshift camps or out on streets in towns as menacing aftershocks and landslides kept nerves on edge.

Jiuzhaigou is an area populated largely by ethnic Tibetans and Qiang people. Its scenic beauty is popular with Chinese tourists who flock to its national park, which is a UNESCO World Heritage site, and tens of thousands of visitors were evacuated Wednesday.

But authorities were searching for more, with the Sichuan provincial fire department saying 16 tourists were believed stranded at a lake in the national park.

Yang Yongzhi was among a search team in red jumpsuits and hardhats who were forced by landslides to turn back Wednesday night after trying to press into cut-off valleys.

"This morning we plan to try again," Yang said.

"We're responsible for finding if there are still people trapped over there. We're the first to go check."

The tremor evoked memories of a devastating 8.0-magnitude earthquake in the region in 2008 that left 87,000 people dead or missing, but the impact of Tuesday's disaster was comparatively light.

Authorities brought the death toll up to 20 on Thursday afternoon, while 431 remained injured, including 34 seriously hurt. A Frenchman and a Canadian woman were among the injured.

The quake tore cracks in mountain highways and AFP journalists saw cars that had been smashed by giant falling boulders.

- 'All-out efforts' -

Some buildings in towns bore cracks, but few structures appeared to have sustained heavy damage.

One Jiuzhaigou hotel partially collapsed, however, and a woman's dead body was pulled out of the rubble Thursday morning, provincial fire authorities said. 

It was not known if others were still buried.   

Authorities have said thousands of response personnel were sent into the area.

So far, 200 million yuan ($30 million) in government relief funds has been allocated for quake relief, according to authorities, and the government of Aba prefecture where Jiuzhaigou is located issued an appeal for donations.

The local government said it had repaired 129 telecommunication towers or other installations that were damaged by the quake, restoring communications with much of the affected area.

More than 30,000 tourists were in the Jiuzhaigou park when the quake struck, but authorities said most were evacuated Wednesday.

All told, nearly 60,000 people were evacuated from quake-hit towns and villages as more than 1,000 aftershocks hit the region.

The local government of Aba prefecture said 1,680 private homes across Jiuzhaigou's 17 townships suffered varying degrees of damage.

President Xi Jinping had called earlier for "all-out efforts to rapidly organise relief work and rescue the injured" in the Sichuan quake.

Source: AFP