Jakarta: A powerful earthquake struck off the western coast of Indonesia's Sumatra Island and triggered a tsunami warning, and a strong aftershock hit the same fault line hours later, agencies said.

There were no reports of damage or injuries from either quake.

The Pacific Tsunami Warning Centre said "there was a very small possibility" of a tsunami following the second quake yesterday, which the US Geological Survey said had an initial magnitude of 6.7. Indonesian authorities did not issue an alert and more than 1 1/2 hours later, no large waves had hit the coastline closest to the epicenter, witnesses said.

"People did not really care because such a tremor is nothing new," said Erwin, a receptionist at a hotel in the coastal Sumatran town of Padang. "It was just like the one in the afternoon," said Erwin, who like many Indonesians goes by a single name.

Indonesia, which straddles a series of active fault lines, is prone to seismic and volcanic activity. A huge earthquake along the same coast spawned the tsunami that killed more than 230,000 people in a number of countries in December 2004.

The first quake yesterday had a magnitude of 7.3 and was centered in the Indian Ocean around 160 kilometres from the town of Bengkulu, said Indonesia s geophysics agency and the US Geological Survey.

It was the latest of several quakes to shake the region in recent days.

Residents in Bengkulu, Padang and the nearby town of Mukomuko said they felt the quake strongly and that many people fled their houses.

Source : PTI