Jakarta, Oct 2: An undersea earthquake measuring 6.4 on the Richter scale hit Indonesia's southwestern Sumatra today, prompting the country's meteorology agency to issue a tsunami warning.
There were no immediate reports of any casualties or damage after the tremors that struck around the same area where a strong earthquake and powerful series of aftershocks killed 25 people and damaged more than 80,000 buildings last month.
The epicentre of the quake lay at a depth of 20 km (12 miles), about 160 km southwest of Lais district in Bengkulu province, the agency said in a text message.
''It was quite strong. People panicked because they are still traumatised by the previous earthquakes. All of us ran out of the building,'' said Evi Nurhidayati, a police officer in Bengkulu.
Since last month's earthquake, the area has been hit by a series of quakes and strong aftershocks, setting off tsunami warnings in Indonesia and other countries in the region.
Indonesia, which is situated along a belt of intense seismic activity known as the ''Pacific Ring of Fire'', was hit by a huge earthquake in December 2004, triggering a devastating tsunami in the Indian Ocean that killed more than 230,000 people in the region, including 170,000 Indonesians.