A strong 6.4-magnitude earthquake struck off Indonesia's Moluccas islands on Sunday, the US Geological Survey said, revising down a preliminary reading of 6.8.
The quake struck in the Moluccas Sea, 169 kilometres (105 miles) northwest of the city of Ternate at around 11:05 pm (1505 GMT) at a depth of 69 kilometres. No tsunami warning was issued.
"So far we have not received any information about what has happened, but there is no tsunami warning," Indonesia's Meteorology, Climatology and Geophysics Agency technical chief Suharjono, who like many Indonesians goes by one name, said.
Sukarjan, an official of the country's disaster management agency in Ternate, one of the Moluccas islands, said there were no immediate reports of damage or casualties.
"People were sleeping and they ran out of their homes when the ground began to shake. It lasted for 20 seconds, but so far we have no reports of casualties or damage," he said.
The USGS initially reported the magnitude at 6.8, but later downgraded the intensity.
Indonesia sits on the Pacific "Ring of Fire" where continental plates collide, causing frequent seismic and volcanic activity.