The U.S. Geological Survey says the magnitude six-point-three earthquake struck earlier today 50 kilometers from West Sumatra's provincial capital, Padang. Two hours later, an aftershock of magnitude 6.1 struck the area again.
Some buildings have collapsed and several homes and other buildings are badly damaged. The quake caused panicked residents of Sumatra to run from buildings, including patients in a hospital in Padang.
It is not immediately clear how many people have been injured.
The quake was felt hundreds of kilometers away in Malaysia and prompted the evacuation of several buildings in Singapore.
No tsunami warning was issued. Reports say electricity in some areas of Sumatra has been cut off.
Information for this story is provided by AFP and AP.