A 6.6-magnitude earthquake struck off the west coast of Indonesia's Sumatra on Friday.

The United States Geological Survey said the shallow quake hit at 12:30 near the island of Nias, about 250 kilometers south of the city of Sinabang.                 

Nias Search and Rescue Agency's spokesperson Agus Wibisono said so far there have been no reports of damage or casualties, however, strong tremors caused panic among those living around the coast fearing a tsunami.