The incident happened inside a house in Viking Mews, Thetford, at about 12.25pm on April 1.
A woman in her 20s and a teenage boy both suffered arm injuries.
Emergency services in Viking Mews
Pit bulls have a feared reputation because they were bred and exploited for fighting, leading to a spate of serious attacks that have drawn intense media coverage over the years.
Campaigners and vets stress that poor training and neglect, rather than the breed itself, are usually to blame for the incidents, but the stigma persists.
Several police cars and ambulances, as well as the East Anglian Air Ambulance, were sent to the neighbourhood after the attack.
The woman was taken to the West Suffolk Hospital for treatment and has since been released, and the boy was treated at the scene.
A man in his 40s was arrested at the scene on suspicion of being in charge of a dangerously out-of-control dog.
He was taken to Wymondham Police Investigation Centre for questioning before being released on bail until June 1.
