The quake struck at 2:53 a.m. Jakarta time on the day with epicenter at 165 km northwest Maluku Tenggara Barat district and with the depth of 11 km under sea bed, Muhammad Fadilah, an official in charge at the agency, said.
There was no tsunami alert issued.
Earlier, the US Geological Survey (USGS) said a 5.9-magnitude quake struck off Saumlaki village on Maluku province’s Tanimbar archipelago at 07:53 p.m on September 21.
Indonesia experiences frequent seismic and volcanic activity due to its position on the Pacific "Ring of Fire".
Last year, a 7.5-magnitude quake and a subsequent tsunami in Palu on Sulawesi island killed more than 2,200 people, with another thousand declared missing.
