A SMALL home-made device exploded in a toilet in the restroom of a fast food outlet in western Sydney but no one was injured, police say. The device was detonated in the men's toilet cubicle at a McDonald's restaurant on High St in Penrith at around 9.10pm (AEDT) yesterday. "The explosion damaged the toilet cistern and an air vent," NSW police said today in a statement. "There was nobody in the restroom at the time. "The remnants of a crudely made explosive device was found and taken for forensic examination."