Powerful earthquake off Sumatra

A powerful earthquake has struck off the Indonesian island of Sumatra, reports say.

Indonesia's meteorology agency said the quake had a magnitude of 6.7, while the US Geological Survey put its strength at 6.8.

The undersea quake was at a depth of 23km (14.3 miles) and the epicentre was 142km south-west of the city of Bengkulu, the agency said.

There have been no reports of any damage or casualties.

The earthquake struck at 2101 local time (1601 GMT) and was followed 10 minutes later by an aftershock with a magnitude of 5.7.

The Pacific Tsunami Warning Centre said there was no threat of a widespread tsunami. However, it said there was a "very small possibility of a local tsunami."

No panic

Haris Said Hakim, a geological agency official based in Bengkulu, said there was no sense of panic in the city.

Last week Indonesia launched a tsunami warning system, although experts say it will not be fully operational until 2010.

Indonesia is prone to seismic activity due to its location on the so-called Pacific "Ring of Fire," an arc of volcanoes and fault lines that encircle the Pacific Basin.

A massive earthquake off Sumatra in December 2004 triggered a tsunami which swept across the Indian Ocean, killing more than 230,000 people.