A 6.1 magnitude earthquake shook southern Mexico on Saturday morning, the US Geological Survey said, rattling a country still coming to grips with the devastation from two stronger temblors earlier this month.

Saturday's quake was centered in Oaxaca state, about 275 miles southeast of Mexico City. Roughly speaking, the epicenter was between the centers of this month's two more violent Mexico earthquakes -- the 7.1 magnitude temblor that hit Tuesday closer to the capital, and the 8.1 magnitude quake that struck September 8 off the country's southern Pacific coast, near Chiapas state.

Mexico City did not immediately appear to sustain significant damage in Saturday's quake, the country's office of the secretary of public security said.

A 6.1 magnitude quake can produce strong shaking and considerable damage to poorly built structures and slight to moderate damage in better-constructed buildings, the USGS says.

The two earlier quakes killed hundreds of people and turned buildings into dust and debris in parts of Mexico. At least 298 people have been reported killed in Tuesday's quake; nearly 100 were reported killed in the September 8 temblor.