Jakarta - A second quake measuring 6.9 magnitude on Thursday jolted West Sumatra, Jakara, the same place hit by a 7.6-magnitude quake on Wednesday.
According to the US Geological Survey, the quake occurred at 8:52am local time on Thursday on Sumatra island, about 280 kilometers from the epicentre of the previous quake.
There has been no report of death or damage from the new quake yet but the Indonesian geophysics and meteorology agency said there were several heavily populated towns nearby.
"The latest quake could have been triggered by the West Sumatra quake yesterday. The pressure from the two plates colliding might have caused the rear of either plates to break and this likely triggered the latest quake," Suharjono, the agency's technical chief said.
Despite the data issued by National Disaster Mitigation Agency that the death toll has reached more than 200, Indonesian Health Minister Siti Fadilah Supari feared that the death toll number could be increasing up to thousands.
"It could be more than thousands, if we look at how widespread the damage is ... but we don't really know yet," the minister said on Thursday.
The quake on Wednesday, occurred at 6:48am Samoa local time and was centered 195 km south of the Samoa capital of Apia with a depth of 18km.