An earthquake measuring 6 on the Richter scale rocked Sumba island of Indonesia on Tuesday, barely four days after a 7.5 magnitude quake hit its Sulawesi island triggering a tsunami and killing 832 people.
This quake came 15 minutes after another one of magnitude 5.9 in the same area.
No tsunami alert was issued on Tuesday and there was no report of damages so far, an official said.
The meteorology and geophysics agency said the quake hit at 7.16 am at a depth of 10 km under the seabed with its epicentre 66 km southwest Sumba Timur.
Spokesman of the national disaster management agency Sutopo Purwo Nugroho told Xinhua that the quake triggered panic but did not result in damages.
Indonesia sits on a vulnerable quake-stricken area called the Pacific Ring of Fire, making it prone to earthquakes.
