TULTEPEC, Mexico >> President Enrique Pena Nieto pledged on Thursday to help rebuild a fireworks market where explosions killed at least 35 people and reopen it next year, while a Roman Catholic church held funeral Masses throughout the day.

Families packed Our Lady of Loreto Catholic Church in Tultepec in Mexico State, where chain-reaction blasts destroyed the country’s best-known fireworks market Tuesday. Investigators have still not announced the cause of the tragedy, which was the third explosion at the market since 2005 and cast a pall over Mexico’s Christmas season.

Pena Nieto visited the injured in a hospital near Tultepec. But it was later at an anniversary ceremony for one of Mexico’s independence heroes that the president spoke about the future of the San Pablito fireworks market.

“We commit to support all of the artisans, the 300 vendors from this market, to recover or to support them so that they can restart their normal activities next year and we can achieve the reconstruction of that market,” Pena Nieto said.

Vendors have said that while they recognize the dangers of the fireworks market, it is their only way to make a living and they would return to work there.

Safety measures were put in place after the previous two explosions at the market but were apparently ignored.

Investigators were focusing their attention on reports that vendors displayed fireworks outside their concrete stalls in the passageways that were designed as safety buffers to prevent exactly the sort of devastating chain-reaction explosions that occurred.

Refugio Leon, whose family ran seven stalls in the market, said vendors commonly stacked displays of bottle rockets and firecrackers outside their establishments in the passageways in violation of the rules.

“Everybody did it,” Leon said, speculating that it may have played a role in the rapid spread of the explosions.

Video and photos of the stalls from previous years show concrete-block enclosures with open dirt passageways between them. Later photos show the passageways filling up with fireworks and awnings.

Because it was the holiday season, the market was packed with fireworks and bustling with hundreds of shoppers when the blasts reduced the market to a stark expanse of ash, rubble and scorched metal. Dramatic video of the disaster showed a towering plume of smoke that was lit up by a staccato of bangs and flashes of light.

On Dec. 12, the city of Tultepec had issued a statement calling San Pablito “the safest market in Latin America.” It said 100 tons of fireworks were expected to be sold during the high season, which runs from August to New Year’s.

The city quoted Juan Ignacio Rodarte Cordero, director of the state’s Fireworks Institute, as saying that “the stalls are perfectly designed and with sufficient space between them to avoid any chain of fires.” City officials said the stalls were equipped with trained personnel, sand, shovels and fire extinguishers.

But during a recent visit to the market, little of that safety equipment could be seen. And when Tuesday’s explosions began, vendors and customers didn’t have time to look for it — or even, in many cases, to run.

Deadly fireworks explosions have also occurred elsewhere 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; in 1988, a fireworks blast in Mexico City’s La Merced market killed at least 68; and in 2013 a rocket struck a truck loaded with fireworks for a religious procession in Tlaxcala state, killing 17 people.