Scores more were injured – including over a dozen children with severe burns – at the San Pablito market in Tultepec, about 30 kilometres north of the capital.
Within minutes some 80 percent of the market had been destroyed.
“We were in the area of the bathrooms when there was an explosion at a shop at the end of the row, and then a series of blasts came one after the other, and people started to fall down a lot,” said Federico Juarez, an eyewitness.
“They started running and then many people were falling over. And pieces of concrete and brick started falling all over the street.”
It’s not yet known what caused the fireworks to ignite.
However this is the third time in just over a decade that explosions have struck the site. In September 2005 there was another blast just before independence day celebrations, which caused many injuries.
The latest disaster happened in the run-up to the busy Christmas holiday. Fireworks are popular in Mexican celebrations.
The local head of emergency services has said poor safety standards were the likely cause of the blasts.
Police have sent a forensic team to investigate and the federal attorney general’s office has opened an investigation. (Alasdair Sandford - Euronews)