A fire that broke out at a discount shop in Mexico has killed at least 23 people and injured 11 others, local officials say.

The blaze broke out on Saturday in the centre of the north-western city of Hermosillo at a branch of Waldo's - Mexico's largest discount chain.

Multiple local authorities described the incident as an explosion, though regional Governor Alfonso Durazo said the exact cause had yet to be determined. The Sonora state public security secretariat said it had ruled out the possibility it was an attack or act of deliberate violence against civilians.

Children are among the victims, officials said, with a 15-year-old girl among those taken to hospital.

Images from the scene show thick, black smoke billowing from the building, with the flames appearing to have spread to cars parked in front of the shop.

After the fire was extinguished, scorch marks could be seen on the shop's doors and windows, with severe damage evident. 'To the families who lost a loved one... I share your pain and offer you my full solidarity,' Durazo said in a video address.

He added that an 'extraordinary, transparent and thorough' investigation had been launched to clarify the causes of the incident and determine who was responsible.

Mexican President Claudia Sheinbaum expressed her condolences to the families and loved ones of those who lost their lives.

The fire coincided with the Day of the Dead weekend, a time of remembrance and festivities in Mexico, leading to the cancellation of planned cultural events by the state government.