The quake, which measured 6.1 on the Richter scale, occurred in Sichuan province in southeastern China near the city of Yaan at 5pm local time on Wednesday.
Another quake with a magnitude of 4.5 was measured a few minutes later, according to the Chinese earthquake authority.
So far, at least four people have been reported dead and at least 14 more have been injured, Chinese state media said.
But the actual number is judged to be significantly more.
Caused landslides
The earthquake, which is said to have occurred at a depth of 17 kilometers, has caused large landslides with great devastation as a result.
Both homes and a factory are said to have been destroyed so far.
Movies show how land and buildings shake.
During the day, more than 4,500 rescue workers were sent to the area to rescue victims.
Local authorities stated on Wednesday that "the focus is on rescuing those who have been locked up and reducing the number of deaths as much as possible", reports AP.
As recently as 2013, the city of Yaan was hit by a powerful earthquake in which over 100 people died and thousands more were injured.