The quake hit Ludian at 7:11 PM yesterday at a depth of 10 km, according to CENC.
All the injured have been rushed to hospital for treatment.
Residents living near the epicenter said the tremor was "quite strong," state run Xinhua news agency reported.
A section of the road to Longtoushan township has been closed due to falling rocks.
A magnitude 6.5 earthquake hit Ludian in 2014, killing 617 people and leaving tens of thousands of houses collapsed or severely damaged.