A tsunami warning has been issued after the quake hit near Chiapas, in southern Mexico along the Middle America Trench, according to the US Geological Survey (USGS).
Pacific Tsunami Warning Centre warned widespread, hazardous tsunami waves were possible.
Meanwhile buildings shaking have been reported in the capital, Mexico City.
An witness said people in Mexico City ran out into the streets after the quake struck.
The news comes as at least 14 people have been killed by Hurricane Irma in the Gulf of Mexico.
At 11pm EDT the National Hurricane Center announced additional Hurricane and Storm Surge Warnings for Florida and the Florida Keys, upgrading from an initial public advisory at 8pm EDT.
Irma is just 585miles from Miami, Florida and is currently around 55miles east north-east of Great Inagua Island in the Bahamas.
The NHC said: “A Storm Surge Warning has been issued from Jupiter Inlet southward around the Florida peninsula to Bonita Beach, as well as for the Florida Keys.
“A Hurricane Warning has been issued from Jupiter Inlet southward around the Florida peninsula to Bonita Beach, as well as for the Florida Keys, Lake Okeechobee, and Florida Bay.”
More to follow…