"It was horrible," said Cecilia Gomez, standing with her family outside her home. "It really scared me."
Daniel Roque, of southern Chiapas state's civil protection agency, said some residents reported panic attacks, but no damage was registered.
The U.S. Geological Survey said the quake struck at 6:50 a.m. (7:50 a.m. EST) and was centered 70 miles southwest of Tuxtla Gutierrez, near the border between Oaxaca and Chiapas states.