SANTIAGO (AFP) - A 6.7 magnitude earthquake struck a region along the border of Chile and Argentina on Wednesday, the US Geological Survey said.

The USGS initially reported the quake, which hit at 1857 GMT (2.57am on Thursday Singapore time), as having a magnitude of 6.9 but later revised the reading.

In its later report, it put the quake's location at 93km west of El Aguilar, Argentina, near the border with Chile.

Its depth was given as 190km, after an initial report that it occurred at a depth of nearly 269km.

The National Seismologic Centre at the University of Chile put the magnitude at 6.6 on the Richter scale. The USGS uses the Moment Magnitude scale.

"There are no preliminary reports of injuries, impact on basic services or infrastructure damage," said Chile's National Emergency Office.

The Chilean Navy's Hydrographic and Oceanographic Service said there was no risk of a tsunami.

A 5.8 magnitude quake hit the same region hours earlier.