An explosion at the open-air fireworks San Pablito Market in Tultepec, Mexico on Tuesday morning, killed 31 people and injured 70 others.

The explosion does not seem to be a terror attack. Similar fires have occurred in the years 2005 and 2006, as a result of holiday celebrations involving fireworks and rockets. However, authorities are still investigating the cause of the explosion.

Mexico Governor Eruviel Ávila Villegas said at a press conference 26 people were killed at the scene, and the other three died in the hospital.

"My condolences to the families of those who lost their lives in this accident and my wishes for a quick recovery for the injured," tweeted Mexican President Enrique Peña Nieto.

National Coordinator for Civil Protectin Luís Felipe Puente said homes in the area had been damaged, and asked civilians to give the scene a three-mile berth in order to avoid danger and allow emergency personnel to function efficiently.

Federal police said on Twitter that they were working with other authorities to help the injured. They also asked those in the area to follow instructions from emergency personnel.

Eyewitness Cesar Carmona, 20, said, "People were crying everywhere and desperately running in all directions."

"Everything was catching fire. Everything was exploding. The stones were flying, pieces of brick, everything was flying," said survivor Crescencia Francisco Garcia.

Though Tultepec is known for its pyrotechnics industry, its market is known as one of the safest in Latin America. Previous explosions have caused authorities to insist on fire safety standards designed to prevent flames from spreading.