The quake struck at 10:24 am local time (0654 IST), 351 kilometres east-northeast of the East Timor capital Dili at a relatively shallow depth of 10 km, the US Geological Survey said.
The Pacific Tsunami Warning Center did not issue any alerts following the tremor in the remote region at the eastern end of the Indonesian archipelago between the islands of Timor and New Guinea.
In an initial assessment, the USGS said there was a low likelihood of damage or casualties.
Indonesia sits on the Pacific "Ring of Fire", where tectonic plates collide, causing frequent seismic and volcanic activity.