Mexico City: A gas tanker truck exploded and burned multiple vehicles under a Mexico City highway overpass on Wednesday, killing three people and injuring 70 others, some with their entire bodies charred and others waiting for help in the road with burns and torn clothing.

The crash of the truck carrying more than 13,000 gallons (49,500 liters) of gasoline on a major highway sent flames and smoke billowing over the south of the capital.

Mayor Clara Brugada called the explosion an “emergency” that burned nearly 30 vehicles and left 19 of those injured in grave condition, including the driver of the truck. Among those injured were a baby and a 2-year-old child.

“This is a horrible accident,” the mayor said.

The authorities said the tanker appeared to have tipped over before it exploded. Online images released by officials showed towering flames consuming the vehicle, while videos on social media captured crowds screaming and fleeing. Some clips showed two men with severe burns and shredded clothing as emergency crews rushed past.

Cesar Cravioto, Mexico City’s government secretary, later announced the fire was “completely under control.” Officials said the blaze destroyed 18 vehicles in total.

The overturned tanker bore the logo of the energy company Silza, though a company official told the Associated Press it was not their truck, insisting, “We only operate in northern Mexico.” Silza did not immediately respond to a follow-up email.

Mayor Brugada visited the site shortly after the blast, where firefighters and medics worked to contain the fire and treat victims. Streams of water poured onto the burning tanker as thick smoke billowed across the east side of the city.

The explosion struck one of the capital’s busiest highways leading toward Puebla. Officials said the roadway would remain closed until further notice.