WASHINGTON (AFP) - Chileans will be feeling aftershocks following last weeks 8.8-magnitude earthquake for months and possibly years, scientists said Friday, as three strong tremors rocked the country. The larger the earthquake, the larger the aftershocks, the more of them and the longer theyre going to last, said John Bellini, a geophysicist at the US Geological Survey (USGS) in Colorado. They will wind down in number, but they will probably be noticeable to people for months and could go on possibly for years, he told AFP. Chile has been rattled by more than 200 aftershocks since the historic monster quake struck the South American country six days ago, killing some 800 people as buildings collapsed and tsunamis swept people to sea. One reason is because the Chile earthquake was a lot bigger than the quake in Haiti - it released about 500 times more energy, explained USGS geophysicist Jessica Sigala. Its a lot of energy thats released, and the Earth is trying to get back to normal. In order to do that its still moving, and thats what the aftershocks are. Scientists believe aftershocks could still be occurring years after the 9.1-earthquake off the coast of Indonesia in 2004, which triggered a deadly tsunami that killed around 200,000 people in south Asia. There was a 9.1 that happened in December 2004 and then there was an 8.6 that happened in March 2005, and occasionally today, well see an earthquake in that area that may be an aftershock from the one that happened in 2004, Sigala said. Meanwhile, three powerful aftershocks Friday spread new terror among weary Chileans traumatised by a huge quake and tsunami. A first 6.2-magnitude quake jolted people awake at 6:20 am (0920 GMT), just six days after Saturdays record 8.8-quake and ensuing tsunami waves killed over 800 people and left some two million homeless. That was then followed Friday by a 6.8-magnitude tremor - one of the most powerful of more than 200 to rattle Chile since the weekend - followed swiftly by another measuring 6.6. The government has declared a period of national mourning as divers searched for bodies and discrepancies emerged over a death toll potentially lower than official figures for the killer earthquake and tsunami. As rescue dogs combed the fetid coastline, where emergency personnel believe huge waves swept hundreds to their deaths, the government said three days of mourning would be observed from Sunday in honour of the quake victims.