LONDON (REUTERS) - A magnitude 6.8 earthquake struck off the coast of Chile on Monday, the US Geological Survey said.

The quake was 640km west of Puerto Aisen at a depth of 10km, USGS said.

Chile's emergency office said on Twitter that the quake did not have the conditions necessary to generate a tsunami. It added the quake was not felt in the country.

The USGS pinpointed the quake in the Nazca tectonic plate area.