The agency said the quake hit at 4:54 pm local time (0224 IST Monday) in the Pacific Ocean 22 kilometres (14 miles) west of Iquique, Chile, at a depth of 35.7 kilometres.
There were no immediate reports of injuries or damage, according to the national emergency office ONEMI.
An 8.2-magnitude quake in the same area in April killed six people and forced a million to leave their homes in the region around Iquique, 1,800 kilometres north of the capital Santiago.
