A massive explosion at a huge fireworks market near Mexico City killed at least 29 people Tuesday and injured 70.
The market in Tultepec was packed with shoppers buying fireworks for traditional Christmas and New Year parties.
Emergency crews needed to wait several hours until the explosions died down, so they could approach the site to look for victims.
Officials say every stall in the market was destroyed and a number of nearby cars and buildings were damaged.
A thick cloud of smoke hovered over Mexico City.
Mexican President Enrique Pena Nieto tweeted his condolences to the families of those killed and hopes for a speedy recovery for those who were hurt.
Television images showed a flurry of pyrotechnics exploding into the early afternoon sky as a giant plume of smoke rose above the market. Fireworks detonated in a peal of clattering bursts reminiscent of a war zone.
The technicolor blast was the third such explosion in just over a decade to hit the popular San Pablito marketplace in Tultepec, about 20 miles (32 km) north of Mexico City. The detonations struck in the run-up to the busy Christmas holiday when many Mexicans stock up on fireworks.
"People were crying everywhere and desperately running in all directions," said 20-year-old witness Cesar Carmona.
Some 13 children suffered burns to over 90 percent of their bodies and were being sent to the U.S. city of Galveston in Texas for treatment, said Eruviel Avila, the governor of the State of Mexico where Tultepec is located. He put the death toll at 29.
Avila also vowed to find and punish those responsible for the blast and provide economic assistance to those who had lost their livelihoods.
Isidro Sanchez, the head of Tultepec emergency services, said a lack of sufficient safety measures was the likely cause of the blast.
The federal police said it had sent a forensic team to investigate the incident, adding that at least 70 people had been injured. Videos from the scene showed people frantically fleeing, while aerial footage revealed blackened stalls and a flattened tangle of metal and wood.
Over 80 percent of the 300 stalls at the market were destroyed by the explosion, said state official Jose Manzur.
Local media reported there were 300 tons of fireworks at the market at the time of the explosion.
Federico Juarez was present when the first explosion rocked the market.
"Everyone started running to escape as bricks and pieces of concrete fell everywhere," said Juarez.
Blasts and fires at the same market destroyed a number of stalls in 2005 and 2006.
Some material for this report came from Reuters.