The earthquake that struck Indonesia Thursday morning had a magnitude of 7.1 on the Richter scale and led to a tsunami alert.

The earthquake hit at 4:02 a.m. (2102 GMT), 135 km west of Bengkulu, a coastal town of Sumatra Island and according to the U.S. Geological Survey, it was at 30 km (18.6 miles) beneath the ocean floor, quite shallow.

An immediate tsunami alert was released by the Indonesian Meteorological Agency. No casualties have been reported.

Geophysicist Gerard Fryer, at the Honolulu-based U.S. Pacific Tsunami Warning Center, said that if a tsunami happens it could only threaten an area about 100 km from the epicenter and its waves would reach no more than 1 meter in height. Since the big waves never came, the tsunami warning was lifted later on.

Last month, the same area was hit by a powerful earthquake measuring 7.8 and 7.1 magnitude on the Richter scale, which killed 23 people and destroyed several buildings.

Since then the area has been hit by hundreds of aftershocks even earlier this month leaving the residents of Bengkulu jittery. When the quake happened this morning, everybody fled their homes to their cars or motorcycles.

The tremor on Thursday was another aftershock of the quake that happened last month, according to Suhardjono, a senior official at Indonesia's Meteorological and Geophysics Agency, who made the statement for el-Shinta radio.

Because of its location, on the “Pacific Ring of Fire,” an arc of volcanoes and fault lines, Indonesia is prone to seismic activity.

On December 26, 2004, a quake measuring 9 on the Richter scale hit the coast of Sumatra Island causing a massive tsunami and killing more than 230,000 people in a dozen countries.

A Red Cross official confirmed that the earthquake this morning was felt very strongly but no damages were done in Bengkulu. According to media sources, Firwan Chairil of the National Disaster Management Office in Jakarta, said by telephone “There has been no tsunami so far and up until now there is no damage or casualties.”