Isa disclosed this while conducting newsmen round the affected offices on Tuesday.
He said the fire affected the Internet, Accounts Department, Head of Gas and Down Stream offices.
He added that “a neighbour vulcanizer rushed to notify the Head of Inspection that he noticed smoke coming from one of the offices.
“The fire started around 3.30 a.m. when most of the staff had gone for monitoring.
“Though the cause of the fire is being investigated, preliminary report shows that it may be as a result of electrical fault.”
He said the fire caused one of the batteries powering the Inverter to explode, resulting in serious damage.
Isa explained that prompt intervention by officials of the state fire service prevented the fire from escalating.
He added that some vital equipment and documents were damaged in the incident.