A 6.2-magnitude earthquake shook the southern part of Mexico's Baja California peninsula and was felt strongly in the city of La Paz.
State civil defence director Carlos Rincon said there were no immediate reports of damages or injuries in La Paz, a tranquil fishing and resort city.
"We are calling on the public to remain calm in case there are aftershocks," he said.
State governor Marcos Covarrubias said schools in the state would be shut so experts could investigate any possible damage to their buildings.
The US Geological Survey said the quake occurred at about 4.45pm local time on Tuesday (11.45pm BST) and was centred about 47 miles north north-east of La Paz in Baja California Sur.
About twenty minutes later, a 4.6-magnitude aftershock occurred about 24 miles north of La Paz, along with a 4.8 temblor about eight miles further out in the Gulf of California about 12 minutes later.