The death toll following the devastating Mexico earthquake now stands at 216, according to the country's civil protection agency, The Independent reports.

Interior Minister Miguel Angel Osorio Chong had earlier said the total was at least 226, but this was quickly revised up to 248 on Wednesday, September 20 morning, before coming back down.

Central Mexico was struck by a 7.1 magnitude quake yesterday evening and a citywide recovery operation is currently underway in the capital.

Some 86 people are thought to have died in the city itself.

Among those killed were at least 20 children in a school where buildings collapsed.

A mix of neighborhood volunteers, police and firefighters used trained dogs and their bare hands to search through the school's rubble. Reports swept through the crowd of anxious parents outside the gates that relatives in two families had received Whatsapp messages from girls trapped inside, but that could not be confirmed.

The rescue effort continued through the night, the work punctuated by cries of "quiet" so searchers could listen for any faint calls for help.

Dozens of buildings were felled by tremors on Tuesday, and power was knocked out for 40 per cent of Mexico City and 60 per cent of Morelos state, to its south.

According to CNN Español, about four million people are without electricity.