More than 60 people have died in the most powerful earthquake to hit Mexico in more than eight decades, ABC News reports.

This time damage to the city was limited, as the quake was deeper and further from the capital.

The southern town of Juchitan in Oaxaca state, near the epicentre, was hit particularly hard, with sections of the town hall and other buildings reduced to rubble.

"The situation is Juchitan is critical, this is the most terrible moment in its history," mayor Gloria Sanchez said.

President Enrique Pena Nieto said in a televised address that 61 people were killed: 45 in Oaxaca state, 12 in Chiapas and 4 in Tabasco — and he declared three days of national mourning.

Rescue workers searched through the night for anyone trapped in collapsed buildings, but by early on Friday the toll appeared to be less severe than that seen in many far less powerful tremors.

Windows were shattered at Mexico City airport and power went out in several neighbourhoods of the capital, affecting more than 1 million people.