At least 58 people were killed after a massive 8.2-magnitude earthquake struck the coast of southern Mexico, toppling homes in Chiapas state and setting off a tsunami warning.
Officials evacuated residents along the central and southern Pacific coast as seismologists warned a tsunami of more than three metres could be headed toward land, affecting coastal towns as far south as Ecuador. This tsunami warning was later called off.
The quake hit offshore at 11.49pm on Thursday, about 100 kilometres from the coastal town of Tonala in far southern Chiapas state, Mexico's seismologic service said, giving an updated magnitude of 8.2.
"It was a major earthquake in scale and magnitude, the strongest in the past 100 years," said president Enrique Pena Nieto in an address from the National Disaster Prevention Centre's headquarters, where he was supervising the emergency response.
The US Geological Survey put the magnitude slightly lower, at 8.1. That is the same as a devastating 1985 earthquake that killed more than 10,000 people in Mexico City - the country's most destructive ever.
The death toll jumped from 36 to 58 in a matter of hours as more bodies were found in the rubble. The state governor said 17 of the deaths were recorded in the town of Juchitan, where a hotel collapsed and several houses were damaged.
The national disaster management agency had earlier reported a total of 15 deaths.
"The house moved like chewing gum and the light and internet went out," said Rodrigo Soberanes, who lives near San Cristobal de las Casas in Chiapas, a poor state with a largely indigenous population and also popular with tourists.
Chiapas governor Manuel Velasco said three people were killed in San Cristobal, including two women who died when a house and a wall collapsed. Two children died in the neighbouring state of Tabasco, the governor there said.
The quake was so powerful that frightened residents in Mexico City more than 1,000km away fled apartment buildings, many in their pyjamas, and gathered in groups in the street.
Buildings swayed strongly for more than one minute, loosening light fixtures from ceilings. Helicopters crisscrossed the sky above Mexico City with spotlights. Some neighbourhoods lost electricity supply.
In neighbouring Guatemala, president Jimmy Morales called for calm on national television while emergency crews checked for damage. Local radio in the Central American country reported one death, but it could not be confirmed.
"We have reports of some damage and the death of one person, even though we still don't have exact details," Mr Morales said. The yet-to-be-confirmed death occurred in San Marcos state near the border with Mexico, he added.