A gas tanker reportedly overturned, triggering an explosion that killed at least three people and injured dozens of others in Mexico.

Horrifying CCTV footage shows a busy highway suddenly engulfed in a cloud of smoke before flames swept through the area on the afternoon of Wednesday, September 10.

Authorities said the truck was carrying more than 3,000 gallons (49,500 litres) of gasoline.

Mayor Clara Brugada described the incident as a 'horrible accident' that burned around 30 vehicles near the border between Mexico City's Iztapalapa district and Chalco in neighbouring Mexico State.

Seventy people were injured, 19 of whom were reported to be in critical condition - including the truck driver.

Brugada said: 'We will continue to provide medical support to the victims. An investigation has already begun to determine the causes of this incident.'

Mexican President Claudia Sheinbaum offered condolences to the families of those who died and thanked emergency responders for their swift action.

The highway was reopened later that evening.