An earthquake measuring 6.1 on the Richter scale jolted Indonesia's Nusa Tenggara province on Sunday, but no tsunami alert was issued.
The quake struck at 4.54 a.m., with the epicentre at 148 km northeast of Alor and the depth at 573 km under the sea bed, said an official of the meteorology and geophysics agency.
"This quake did not have a potential of tsunami, so that we did not issue an alert," the official told Xinhua news agency.
There were also no reports of damages or casualties.
Indonesia is prone to quakes as it sits on a vulnerable impact zone called the Pacific Ring of Fire.