Workers at some Mexico City office towers temporarily evacuated their buildings but quickly re-entered after the swaying stopped.
The U.S. Geological Survey said the quake occurred around 8:30 a.m. local time (13:30 GMT) and was centered near the city of Huajuapan de Leon in southern Oaxaca state, about 140 miles (230 kilometers) southeast of the capital.
One minute before the earthquake, a small explosion was recorded at Mexico’s most active volcano, Popocatepetl, known in Mexico as Popo.
The federal civil defense agency said there were no immediate reports of incidents.
On Sept. 19, a magnitude 7.1 earthquake damaged or destroyed hundreds of buildings and killed 228 people in Mexico City and 141 others elsewhere.
— SkyAlert (@SkyAlertMx) July 19, 2018