An explosion has ripped through a fireworks market on the northern outskirts of Mexico City, reportedly killing at least 31 people and injuring 70.

The explosion, which was caught on camera, sent a huge plume of charcoal-grey smoke billowing into the sky over the town of Tultepec, the Guardian reports.

Images broadcast by Milenio TV showed smoke rising from the scorched ground and fireworks stands.

“People were crying everywhere and desperately running in all directions,” said 20-year-old witness Cesar Carmona.

Crescencia Francisco Garcia said she was in the middle of the grid of stalls along with a few hundred others when the thunderous explosions began.

As she ran away she saw people with burns and cuts, and lots of blood.

“Everything was catching fire. Everything was exploding,” Francisco said. “The stones were flying, pieces of brick, everything was flying.”

More than a dozen children suffered burns to over 90% of their bodies and were being sent to the US city of Galveston in Texas for treatment, said Eruviel Avila, the governor of the state of Mexico. The state’s top prosecutor raised the death toll late on on Tuesday to 31.

Avila vowed to find and punish those responsible for the blast and provide economic assistance to those who had lost their livelihoods.

The explosion flattened the San Pablito market which is one of the mainstays of the economy in Tultepec and where many people make a living from manufacturing fireworks – often in clandestine workshops.

The Christmas season brings in brisk business, according to merchants at the market, as Mexicans stock up on pyrotechnics.