Norwalk residents are shaken up after a small bomb exploded inside an abandoned school Friday.

The blast took place on Strawberry Avenue, where officials believe an explosive device was place behind the door of the building. No one was inside at the time and no injuries were reported. The Stamford Bomb Squad was called to clear the building.

Area residents say they heard a loud boom and felt their houses shaking. They also reported billowing smoke coming over the building. Anyone with information is asked to contact Norwalk police at 203-854-3031.