Mexico City, Nov 2: At least 22 people were killed, including four children after an explosion triggered a fire at a department store in Hermosillo, capital of the northern Mexican state of Sonora, local media reported.

The explosion occurred in the afternoon at a chain department store in the city center, according to the reports. Witnesses said the fire quickly spread through the building and nearby vehicles, trapping several people inside, Xinhua news agency reported.

Rescue teams rushed to the scene to conduct search-and-rescue operations and transport the 12 injured people to local hospitals.

Preliminary investigations suggest that the fire may have been caused by smoke from a malfunctioning transformer.

The explosion occurred in one of the stores of the local Waldo's chain, after which the building caught fire. Local media noted that those injured had suffered burns​​​.

Authorities in Sonora said the possibility of a terrorist attack has been ruled out.

Earlier in September, three died and over 50 were injured after a gas tanker truck exploded in Mexico City, with 19 of them in serious condition, local authorities said.

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The accident occurred on the Zaragoza road under the Concordia bridge, said Clara Brugada Molina, head of government of the Mexican capital, on the social media platform X.

It took place at around 2:20 p.m. local time when the truck, with a capacity of 49,500 litres, overturned, and the injured have been rushed to different hospitals, she told local media.

The accident also affected 18 vehicles, and 19 of the injured transferred to hospitals are in serious condition.