A strong earthquake measuring 6.6 on the Richter scale struck northwestern Mexico early on Sunday.
There were no immediate reports of damage or injuries and there is no reported danger of a tsunami in the region.
The US Geological Survey (USGS) said the 10-kilometer (six-mile) deep quake hit an area between the tourist resort region of Baja California and the state of Sinaloa
The USGS also reported an aftershock of magnitude 5.2. Temblors of magnitudes of 4.9 and 5.3 had shaken the same area less than 35 minutes before the bigger one.
Baja California is known for its resorts of Los Cabos, which attract tourists from the United States and other countries.
Last week a 5,5 quake struck off the Pacific coast of Mexico 135 kilometers from the town of Pijijiapan and 136 km from the town of Mapastepec.