TULTEPEC, Mexico (AP) -- The San Pablito fireworks market was bustling with hundreds of shoppers when a powerful chain-reaction explosion ripped through its stalls, killing at least 29 people and leaving dozens more badly burned.

The third such blast to ravage the market on the northern outskirts of Mexico's capital since 2005 sent up a towering plume of smoke that was lit up by a staccato of bangs and flashes of light. Once the smoke cleared, the open-air bazaar was reduced to a stark expanse of ash, rubble and the charred metal of fireworks stands, casting a pall over the country's Christmas season.

Mexico State health officials said 72 people were being treated for injuries from Tuesday's explosion, including for severe burns, in some cases over 90 percent of their bodies. Ten children were among the hospitalized. Authorities have not yet said what may have caused the explosions which took place in Mexico State, which rings the capital.

Mexico State Gov. Eruviel Avila reported Tuesday night that in addition to the 26 people who perished at the market, three more victims died later in hospitals.

"We are going to identify who is responsible," Avila said.

Tultepec Mayor Armando Portuguez Fuentes said the market was especially well stocked because demand for noisy firecrackers and rockets soars this time of year.

 

A similar fire engulfed the San Pablito Market in 2005, touching off a chain of explosions that leveled hundreds of stalls just ahead of Mexico's Independence Day. A year later a similar incident at the same market also destroyed hundreds of stands.

Portuguez, the Tultepec mayor, said the manufacture and sale of fireworks is a key part of the local economy. He added that it is regulated by law and under the "constant supervision" of the Defense Department, which oversees firearms and explosives.

Deadly fireworks explosions have occurred with some regularity in Mexico: In 2002, a blast at a market in the Gulf coast city of Veracruz killed 29; in 1999, 63 people died when an explosion of illegally stored fireworks destroyed part of the city of Celaya; and in 1988, a fireworks blast in Mexico City's La Merced market killed at least 68.