A 7.4-magnitude earthquake struck the southern coast of Indonesia's Maluku province on Thursday morning, the country's Meteorological, Climatological and Geophysical Agency said.
No casualties or damage have been reported so far, reports said.
The quake struck at 1.25 a.m. and the epicentre was 45 km northwest of Southwest Maluku Regency, with a depth of 210 km under the sea.
The Agency reported strong tremors in islands and towns closer to the epicentre and also recorded a 5.2-magnitude aftershock near the epicentre.
It did not issue a tsunami alert for the quake, but warned of the possibility of aftershocks near the epicentre and cautioned residents to remain calm and alert.
The US Geological Survey (USGS) put the magnitude at 7.3 with a depth of 166.9 km.
In September 2018, a 7.4-magnitude earthquake struck Donggala Regency in Central Sulawesi province, killing more than 2,000 people in the quake and the tsunami triggered.
Indonesia sits on the so-called Pacific Ring of Fire where several tectonic plates meet, making it vulnerable to frequent earthquakes.
