Earthquake shakes Mexico City
But there were no immediate reports of damages or injuries.
The US Geological Survey said a magnitude-5.5 quake hit at 7:04 am (1304 GMT), centred about 17 kilometres west-southwest of Pinotepa Nacional on the Pacific Coast and 365 kilometres south-southeast of Mexico City.
Mexico Seismology Service initially calculated the quake's magnitude at 5.9.
A second quake shook the region a few minutes later.
Mexico City's soft soil makes it especially sensitive to distant earthquakes. But Mayor Manuel Mancera said in a Twitter post that no damage was reported.
Local news media also said there were no reports of damage close to Pinotepa Nacional.