Chile has been shaken by a strong 6.3-magnitude earthquake that officials said was not an aftershock from the massive quake that killed more than 800 people last weekend.

The head of the Office of National Emergency (ONEMI), Carmen Fernandez, said no damage had been reported but "obviously there is fear among the people".

The quake struck at 7:39pm (local time) and its epicentre was 105 kilometres below the Andes mountains, north-east of Calama, according to the US Geological Survey, which monitors earthquake activity.

Calama, a major centre for mining with one of the world's largest open-air copper mines located nearby, is 2,500 metres above sea level so there is no danger of a tsunami, Mr Fernandez said.

The powerful 8.8-magnitude quake and following tsunami that struck Chile on Saturday killed more than 800 people, according to official figures.

- AFP