A strong 6.6-magnitude earthquake struck offshore in northwestern Mexico early Sunday between the tourist resort region of Baja California and the state of Sinaloa, according to the US Geological Survey.
The 10-kilometer (six-mile) deep quake hit at 3:14 am (0814 GMT) and was located some 59 kilometers southwest of the Sinaloa town of Topolobampo, according to the USGS.
The USGS 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.
There were no immediate reports of damage or injuries.
Baja California is known for its resorts of Los Cabos, which attract tourists from the United States and other countries.