A moderately strong 5.3-magnitude earthquake hit Indonesia's Saumlaki on Monday, the US Geological Survey said, but no tsunami alert was issued.
The quake struck at 226 kilometres northwest of Saumlaki at 1 am at 9:25 UTC (Coordinated Universal Time), the USGS said.
The Pacific Tsunami Warning Centre said there was no tsunami threat and there were no immediate reports of damage.
Indonesia sits on the Pacific "Ring of Fire" where continental plates collide, causing frequent seismic and volcanic activity.
A huge undersea quake in 2004 triggered a tsunami that killed more than 170,000 people in Aceh province, on western Sumatra island, and tens of thousands more in other countries with coasts on the Indian Ocean.