At least three people have been killed and 45 injured in an earthquake in eastern Indonesia, the head of the republic's emergencies center said on Monday.

"Early Monday morning the Sumbawa island was hit by a series of quakes, the most powerful of them, measuring 6.7 on the Richter scale occurred at 2.53 local time (19.53 GMT)," Rustam Pakaya said, adding that the earthquake had killed three people and damaged hundreds of buildings.

The quake's epicenter was 48 km (30 miles) from the coastal city of Raba, at a depth of 45 km (28 miles). After the quake and aftershocks, including one measuring 5.8, a tsunami warning was issued, but later cancelled.

On Sunday night another 6.0 magnitude quake struck the Indonesian island of Sumatra. No casualties have been reported.

The Indonesian archipelago is located at the Pacific Ring of Fire, an area of frequent earthquakes and volcanic eruptions encircling the basin of the Pacific Ocean. The region has seen a period of increased seismic activity since 25 people died in a series of earthquakes in September.

Indonesia was worst hit by the December 26, 2004 earthquake and tsunami, which killed more than 225,000 people in 11 countries.