The quake, around 60 miles southwest of Suchiate in the state of Chiapas, had a magnitude of 5.6.
At least 113 people had been rescued alive after the earthquake.
Scenes of mourning multiplied all along the normally placid Pacific coastline of the South American country.
Up to 2,000 people had been reported as missing.
The death toll from the strongest earthquake in decades in the country has risen over 400.
Hundreds killed by the 7.8 earthquake.
The 7.8 earthquake left thousands wounded.
The magnitude-7.8 quake was the strongest to hit the country since 1979.
A bridge collapsed in the coastal city of Guayaquil and a collapsed tower at the airport in the city of Manta.
English23/03/2016
Earthquake felt in Oaxaca
A 4.9-magnitude earthquake was reported at 18:29 pm.