Mexico ? Flames engulfed a day care center in northern Mexico on Friday, killing at least 29 children and injuring dozens as neighbors and teachers ran through thick, black smoke to pull preschoolers from the blaze, officials said.

The fire may have started at a tire and car warehouse Friday afternoon and spread to the neighboring ABC day care center in the city of Hermosillo, said Jose Larrinaga, a spokesman for Sonora state investigators. But Larrinaga added that the cause of the fire and exactly where it started were still under investigation.

The fire was controlled within two hours and most children died of asphyxiation, he said.