China deployed more than 8,000 soldiers and military reservists to help search and rescue efforts in the southwest Monday after a 6.2-magnitude earthquake that left 40 people dead, state press said.

The weekend quake, in a mountainous region spanning the Sichuan and Yunnan provinces, destroyed or damaged more than 392,000 homes and injured nearly 675 people, according to the Xinhua news agency.

Xinhua was quoting figures announced by the Ministry of Civil Affairs.

The China News Services said earlier Monday the military were rushed to the scene to beef up search and rescue efforts as more people were being located and pulled out from the rubble.

Some 2,000 troops, police and firefighters already in the area have rescued more than 130 injured victims from collapsed buildings since the quake struck on Saturday afternoon, it added.

An inter-ministerial command post was set up on Monday in the quake zone to coordinate communications and the rescue and relief work, the China Earthquake Administration said.

Food, water, medical supplies and tents were being rushed to the scene, it said on its website.

Besides searching for survivors, rescue workers were also rushing supplies to those in need, evacuating people from dangerous buildings, and setting up refugee camps, it added.

The administration said two of the fatalities were attributed to a 5.6-magnitude aftershock that shook the region around Panzhihua city on Sunday afternoon.

Panzhihua is near the epicentre of the main quake and about 500 kilometres (300 miles) south of where an 8.0 earthquake devastated a swathe of Sichuan on May 12, leaving nearly 88,000 people dead or missing.

According to the government in Sichuan, aftershocks continued to rattle the region Monday, shaking the city of Dujiangyan which was also badly damaged in May.

Most of Saturday's damage was in the county of Huili.