Photo for illustration (Source: AFP/VNA)

The dead included at least four firefighters and two police officers who rushed to the scene after the first explosion, only to be killed by a subsequent wave of blasts.

The initial explosion occurred at around 09h30, then spread to other warehouses just as police and firefighters began attending to the first victims.

Mexican President Enrique Pena Nieto sent his condolences to the victims' families on Twitter and said the army and Interior Ministry were supporting the state rescue effort.

The government said first responders were also among the injured. Helicopters took the wounded to several hospitals, and more than 300 police were sent to the scene.

A number of blasts have occurred at the fireworks markets, workshops and depots in Tultepec, about 32km north of Mexico City, including massive explosions in a market in December 2016 that killed around three dozen people./.

Compiled by BTA