A moderate undersea quake measuring 5.8 on the Richter scale jolted Indonesia's Aceh province on Thursday, but there were no reports of any casualties or damage, the Meteorological and Geophysics agency said.
The quake's epicentre was at a depth of 10 km (6 miles) and 354 km (220 miles) southwest of the provincial capital, Banda Aceh. The agency did not issue a tsunami warning.
The US Geological Survey put the magnitude of the quake at 6.2.
Earthquakes are frequent in Indonesia, which lies in the so-called "Pacific Ring of Fire".
In December 2004, a massive undersea quake and tsunami hit Aceh on the northern tip of Sumatra island, leaving as many as 170,000 dead or missing in the province alone.