The cause of a fire at a Portland restaurant in under investigation.

The two-alarm fire broke out Wednesday around 7:45 p.m. at Chez Bujabelle on St. John Street, across from the Union Station Plaza.

The restaurant is on the first floor, where the fire started.

The flames spread to the second floor before they could be extinguished by fire fighters.

Division Chief Shawn Donahue of the Portland Fire Dept. says they put the fire out within a half hour.

No one was inside at the time of the fire, and no injuries were reported.

There was no word Wednesday night on the extent of the damage.