The race to rescue those trapped in the rubble continues, more than 24 hours after a powerful earthquake struck off Mexico’s southern coast.
The 8.1 magnitude quake left at least 61 people dead, according to officials.
Another 200 people were injured, President Enrique Peña Nieto said, as he declared a national day of mourning.
Meanwhile, the feared category one Hurricane Katia, which struck Veracruz on the east coast on Saturday, has been downgraded to a tropical storm.
The US National Hurricane Center reported Katia had been rapidly weakening ever since making landfall, but local officials are worried the storm could still cause landslides and flooding.
Rescue efforts following the earthquake, which struck late on Thursday, are focussing on the worst-hit states of Tabasco, Oaxaca and Chiapas.
Tens of thousands of emergency packs, as well as 100 extra police officers and rescue dogs were sent to Juchitán, Oaxaca, said to be the worst affected town.
The earthquake is the most powerful anywhere in the world since September 2015, but its depth – 70km according to the US Geological Service – means that the shaking felt at the surface was less strong than it would have been for an equally powerful but shallower tremor.
At least 36 people have been reported dead in Juchitán, according to news agency AFP, with the town hall and a number of other buildings destroyed or badly damaged.
“The situation is Juchitán is critical; this is the most terrible moment in its history,” said Mayor Gloria Sanchez.
Police officer Vidal Vera, 29, who had not slept in more than 36 hours, told AFP: “I can’t remember an earthquake this terrible.
“The whole city is a disaster zone right now. Lots of damage. Lots of deaths. I don’t know how you can make sense of it. It’s hard. My sister-in-law’s husband died. His house fell on top of him.”
Peña Nieto, who visited the town on Friday, said flags would fly at half-mast on Saturday out of respect for the dead and bereaved.
The president said 45 deaths had been reported in Oaxaca, 12 in Chiapas and four in Tabasco.