The U.S. Geological Survey says the new earthquake to strike Mexico had a magnitude of 6.1 and was centered in the southern state of Oaxaca. It initially calculated the magnitude as 6.2
The director of Mexico's disaster agency says it's an aftershock of the 8.1 quake that hit on Sept. 7 off the country's southern coast.
The new quake 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.
It's not immediately clear if the new quake caused damage or injury.