A total of 74 people have died and 26 remain missing after a 6.8-magnitude earthquake jolted Luding County in southwest Sichuan Province on Monday, local authorities said on Wednesday.

In addition, 259 people have been injured in the disaster as of Tuesday night, the People's Daily reported.

Authorities have reopened roads leading to the epicentre of Monday's quake and traffic has resumed, state media reported.

The strongest earthquake to hit the province since 2017 destroyed numerous buildings and caused severe damage to power and water infrastructure as well as telecommunications.

Rescuers had rushed to reach stranded people, restore utilities and send emergency relief, while 11,000 people were evacuated on Tuesday from Luding county, where the quake was centred.

Early on Wednesday, China Earthquake Networks Centre recorded a magnitude 3.0 aftershock at the epicentre, at a depth of 12km.

Weather forecasters have also warned of the prospect of heavy rains in the region until Friday. (Xinhua/Reuters)