A MASSIVE explosion has left at least three dead and others running for their lives with a wall of flames hot on their heels.

Terrifying video footage of the moment a gas truck blew up on a major highway has been posted to social media , as the incident was classified as an "emergency".

Multiple videos have surfaced online, showing a wall of flames spread through the air, engulfing everything in its path.

Terror-stricken witnesses fled the scene as thousands of litres of gasoline ignited on the major road in Mexico City.

The explosion left smoke and flames mushrooming around the vehicle, later billowing out across the south of the capital city.

Three people have died and at least 70 others are injured, including the truck driver.

The driver - along with 18 other injured people

See Full Page