A strong aftershock has rolled through Mexico City, swaying buildings and sending some people running into the street.
The quake was much weaker than the magnitude 7.1 earthquake that hit on Tuesday, which killied at least 295 people and knocked down buildings across the capital.
It was not immediately clear if there have been any new injuries or damage from this latest quake.
The U.S. Geological Survey says the new earthquake to strike Mexico had a magnitude of at least 6.1 and was centred in the southern state of Oaxaca.
That's the region most shaken by a magnitude 8.1 quake that hit on Sept. 7.
It also swayed buildings in Mexico City, which is trying to recover from a magnitude 7.1 temblor that struck on Thursday, killing at least 295 people.
A magnitude 8.1 earthquake struck earlier this month near the state of Chiapas.