Firefighters have extinguished a fire inside a Belconnen laundromat overnight.

At about 3.30am, ACT Fire and Rescue responded to reports of a structure fire on Josephson Street.

Upon arrival firefighters located a fire in a laundromat with smoke logging throughout several neighbouring shopfronts.

The fire was quickly contained and extinguished and firefighters checked for fire extension into the roof.

The laundromat itself suffered significant smoke damage, and the surrounding shops suffered minor smoke damage and were able to resume trading today.

There were no reports of injury.