A moderate earthquake measuring 5.0 on the Richter scale rattled Indonesia's Nias island on Tuesday, but there were no reports of casualties, the metereology agency said.
The quake occurred at 7.58 am and was centred 86 kilometres north of the main town Gunung Sitoli, the meteorology and geophysics agency said in Jakarta.
The under-sea quake had a depth of 96 kilometres, it said.
The agency said there were no reports of casualties or damage.
The US Geological Survey put the magnitude of the quake at 5.3.
Nias was one of the areas hit by the massive 2004 earthquake and subsequent tsunami that killed more than 220,000 people around the Indian Ocean, including 168,000 people in the Indonesian province of Aceh.
Three months later, Nias was struck by an 8.7-magnitude quake, which killed 850 people, injured 6,000 and left tens of thousands homeless.
Indonesia sits on the Pacific "Ring of Fire", where the meeting of continental plates causes frequent seismic activity.