This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

A day ago, families wandered through rows of stalls at the San Pablito market north of Mexico City, searching for fireworks to launch during the holiday season.

Police officers stand guard on December 21, 2016 at Mexico's biggest fireworks market in Mexico City's Tultepec suburb after a massive explosion killed at least 31 people. (Credit: PEDRO PARDO/AFP/Getty Images)
Police officers stand guard on December 21, 2016 at Mexico’s biggest fireworks market in Mexico City’s Tultepec suburb after a massive explosion killed at least 31 people. (Credit: PEDRO PARDO/AFP/Getty Images)

Now forensic teams are combing through the charred rubble, searching for victims’ remains. At least 31 people were killed and dozens more were injured in a massive explosion Tuesday at the market, officials said.

The deadly blast sent huge plumes of smoke billowing into the sky and shook the ground in neighboring towns.

A day later, the smell of fireworks, charred buildings and burned plastic still fills the air.

The San Pablito market is in Tultepec, a city about 40 kilometers (25 miles) north of Mexico City that bills itself as the country’s fireworks capital.

An explosion at the same fireworks market in 2005 injured a large number of people and caused enormous damage. But since then, officials have touted security improvements at the market and described it as a much safer place to buy and sell pyrotechnics than the clandestine workshops in some local homes.

Authorities haven’t said what caused Tuesday’s explosion.

Video of the blasts showed flashes of fire and what appeared to be fireworks exploding.

The area is densely populated, and witnesses from surrounding neighborhoods captured the huge volume of smoke that billowed into the sky.

People ran for their lives, witnesses told CNN.

Seventy-two people were injured, said Eruviel Avila, governor of the state of Mexico. Three minors are expected to be transferred to a hospital in Galveston, Texas, for treatment for extreme burns.