Updated

A magnitude-6.5 undersea earthquake shook the western shore of Indonesia's Sumatra island on Friday, causing panic but no casualties or damage, an official said.

The quake struck late at night 74 miles southeast of Pagai Selatan, an island off the western coast of Sumatra, Indonesian Meteorology and Geophysics Agency official Gian Ginanjar said.

The quake struck 6 miles beneath the Indian Ocean bed. There was no tsunami potential, he said.

Edi Firmanto, a resident of the Sumatra coastal town of Bengkulu, said people fled their homes and rushed to higher ground.

"I woke up when I heard my wife screaming in panic and got out with our two children and headed up a hill," Firmanto said.

They went home when a village chief announced that the quake had no tsunami potential.

Indonesia rests on a series of fault lines that make the sprawling archipelago nation one of the most earthquake-prone.