Mexico City - President Enrique Peña Nieto has made a commitment to help the three hundred artisans who lost their livelihoods after last week's deadly explosion destroyed the San Pablito fireworks market.

The cause of the December 20 blast that struck the open-air market in Tultepec, a town on the outskirts of Mexico City, remains unknown.

Alejandro Gomez, the state attorney general, told Mexican television it was unclear what caused the explosions, adding he could not corroborate accounts pointing to a detonation at one stall that may have begun a chain reaction.

The number of people killed has increased to 35, the State of Mexico's government said in a statement Thursday. The latest confirmed victims were a woman and a girl, who both died in hospitals, the government said, noting that 26 people had died at the market, and another nine in hospitals. Dozens more were injured.

During a visit to survivors in hospital, Peña Nieto said, "We made a commitment to support everyone, the 300 stall owners of that market, to recover and support them so that they can continue their activities next year normally."

The economy of Tultepec relies heavily on the pyrotechnics industry. "The artisans are not alone," said Mexico state Governor Eruviel Avila.