A mother and her two small daughters were killed in an explosion at an illegal fireworks factory over the weekend in Culiacan, the capital of the northwestern Mexican state of Sinaloa, officials said.

The blast occurred Sunday at a house where gunpowder was being stored in a residential neighborhood, Sinaloa Attorney General Marco Antonio Higuera said.

"Several crates containing explosive materials and gunpowder for the manufacturing of rockets were found at the site where the explosion happened," Higuera said.

The blast occurred in a house in the Lazaro Cardenas district and damaged seven other houses, the AG said.

Three people were arrested at a nearby house where more explosives were found.

Ana Laura Cruz, 25, and her daughters Guadalupe, 3, and Germayona, 7, were killed in the blast.

Cruz and her daughters were from Puebla, a state in central Mexico, officials said.

Firefighters, emergency management office personnel, Red Cross paramedics, soldiers and police responded to the blast, assisting victims and cordoning off the area. EFE