California's state fire marshal has officially revoked a number of pyrotechnic licenses as the investigation into the deadly fireworks facility explosion in Esparto continues.

The July 1 incident at the Devastating Pyrotechnics facility in Yolo County killed seven people.

Friday, Cal Fire's Office of the State Fire Marshal announced that they had revoked the pyrotechnics licenses of Kenneth Chee and Craig Cutright – two people whose companies, Devastating Pyrotechnics Inc. and Blackstar Fireworks, are being investigated after the explosion.

Officials allege that the entities were found to have violated California's laws regarding fireworks, including not reporting lost fireworks and possessing fireworks without a local fire permit.

"Since the explosion, our arson and bomb investigators and deputy state fire marshals have been laser focused on not only determining the circumstances leading up to the incident, but also whether or not the operators were working with their state issued licenses," said Chief Daniel Berlant, California state fire marshal, in a statement.

A number of agencies are reviewing the incident. Earlier in August, more than a month after the explosion, Yolo County health officials declared a local health emergency as an environmental review was conducted.

Devastating Pyrotechnics and Blackstar Fireworks already had their fireworks licenses suspended by the state after the incident. Both Cutright and Machado have connections to local law enforcement agencies, CBS Sacramento has reported.