A moderate magnitude-5.5 earthquake struck off the coast of Indonesia's Sulawesi island early on Wednesday, seismologists said.
The quake, which hit at 02.06 am (11.36 pm IST on Tuesday) in the Molucca Sea, was centred 205 kms northeast of Manado, on Sulawesi, the US Geological Survey said. It was 60 km deep.
The Indonesian archipelago sits on the Pacific Ring of Fire where continental plates meet, causing frequent seismic and volcanic activity.
Indonesia was the nation worst hit by the earthquake-triggered Asian tsunami in December 2004, which killed some 168,000 people in Aceh province.