Thunderous series of explosions tore through an open-air fireworks market outside Mexico City on Tuesday, leaving at least 29 dead and 72 injured, many seriously, authorities said.

The initial blast occurred at 2:30 p.m., when the market was filled with shoppers looking for fireworks for the holiday season. Video showed what looked like an aerial bombing attack on the sprawling market, as bright flashes punctuated the blue sky and fireballs burst into the air.

Beneath giant plumes of black smoke, the market stalls lay in splinters. Firefighters doused the remaining flames, baring an apocalyptic expanse of twisted debris. The death toll rose through the afternoon. By dark, Eruviel Avila, the governor of the state of Mexico, told local news crews that it stood at 29, with an additional 72 people injured. The casualty figures were expected to rise.

Among those gathered in the chilly evening, there was widespread disbelief about the breadth of the tragedy in a market that was a signature part of the town, a place many had visited - and where hundreds of others made a living.

Fireworks are a common part of Mexican Christmas celebrations, used by families everywhere from the countryside to the heart of the capital. The San Pablito Market in Tultepec, about 25 miles north of Mexico City, was the best-known place to buy them.

In 2005, a fire engulfed the same market, touching off a chain of explosions that leveled hundreds of stalls just ahead of Mexico's Independence Day. A similar fire at the market destroyed hundreds of stands in September 2006.

Juan Ignacio Rodarte Cordero, the director of the Mexican Pyrotechnics Institute, called San Pablito "the safest pyrotechnics market in all of Latin America," according to an August press release from the government of Tultepec, a city of 50,000 in the state of Mexico.

In a press release last week, the market's president, German Galicia Cortes, assured visitors that the market was secure, complete with "fire extinguishers, water, sand, picks, shovels and trained personnel who know how to act in case of any incident."

Mexican Red Cross reported that it had dispatched 10 ambulances with 50 paramedics to the scene. Rescue workers were shown on Mexican TV picking their way through the ruins of  twisted metal, warped roofs and other debris.