Police are searching for a man who allegedly set fire to an electrical box in central Hobart, knocking out traffic lights at a busy intersection.
The incident occurred about 6:30am on Thursday at the corner of Elizabeth Street and Bathurst Street.
Smoke was seen billowing from an underground utility access point on the footpath.
A police officer used a fire extinguisher to put out the blaze while an unmarked vehicle blocked the road.
TasNetworks crews are on site conducting repairs, with lane closures expected to remain in place for several hours.
Motorists have been urged to avoid the intersection.
Police said they want to speak to anyone who saw a man wheeling a large black suitcase in the area around the time of the incident.
Anyone with dash cam or other footage from the area has been asked to come forward.
Information can be provided to police on 131 444 or to Crime Stoppers anonymously.
