Indonesian seismologist Fauzi says there is no risk of a tsunami.
The U.S. agency says Wednesday's quake was centered 56 kilometers (35 miles) under the sea.
Indonesia's Meteorology and Geophysics Agency initially reported a quake measuring a preliminary 6.3 magnitude that was centered about 157 kilometers (97 miles) northwest of Tual in the southeastern part of Maluku province.
It said the epicenter was 12 kilometers (7 miles) deep.
