There were no immediate reports of damage from the quake, which occurred at a depth of around 10 kilometers (six miles).
Officials said there was no risk of a tsunami forming from Saturday's quake.
Mexico has been rattled by a number of sizeable quakes in recent weeks. A a strong tremor hit the capital Mexico City on May 8, causing a bridge to collapse and buildings to sway, but no casualties.
A powerful 7.2-magnitude quake last month near the Pacific coast city of Acapulco also caused some building damage and widespread power outages, but no known casualties.