JAKARTA: Two quakes struck in quick succession off the southern coast of Indonesia's Sumba island on Tuesday (Oct 2) morning, the United States Geological Survey (USGS) said.
A shallow and moderately strong 5.9-magnitude quake struck at 2359 GMT, around 40 kilometres (25 miles) off Sumba, an island of some 750,000 people.
It was followed up some 15 minutes later by a stronger 6.0-magnitude quake in the same area at a depth of 30 kilometres.
"We felt four shakes. People were panicking when the first quake happened and ran out of the hotel, about 40 of our guests," Defis Rinaldi, a worker at the Padadita Beach Hotel told AFP by telephone.
"It was only a few seconds and the geophysics agency didn't issue a warning, everything is back to normal now," he said.
Sumba lies some 1,600 kilometres to the south of Sulawesi island which was struck by a devastating quake and tsunami on Friday which killed more than 800 people.
There were no immediate tsunami alerts or reports of casualties or damage.