A strong magnitude-6.8 earthquake has struck Chile but no tsunami alert has been triggered and there are no immediate reports of damage or injuries, seismologists say.

The quake hit the north-central Coquimbo region at a depth of 36 kilometres at 4:31am local time (6:31pm AEDT), the US Geological Survey (USGS) said, but the Pacific Tsunami Warning Centre did not issue an alert.

The epicentre was close to the coast, 47 kilometres from the city of Ovalle and nearly 300 kilometres north of Chile's capital Santiago.

ONEMI, the national emergency service, initially said that there was the possibility of a "minor tsunami," but a few minutes later called off the warning.

Chile is no stranger to earthquakes.

In September, the same area of the country was hit by a magnitude-8.3 earthquake and tsunami that left 15 dead and over 16,000 homeless.

In February 2010, an 8.8-magnitude quake off the southern Chilean coast killed more than 500 people and inflicted an estimated $30 billion in damage.

Chile lies on what is known as the Ring of Fire — an arc of fault lines that circles the Pacific Basin and is prone to frequent earthquakes and volcanic eruptions.

The country has long put in place anti-seismic engineering systems, applying a technique known as seismic isolation, or base isolation to protect buildings from the Earth's tremors.

ONEMI has also been leading a big push to educate the population, organising frequent drills and visiting schools to simulate earthquake situations.

AFP