British police investigating what is believed to be the shooting of a baby say they are examining whether negligence may have played a part.
The one-year-old boy from Bristol is fighting for life after suffering a serious head injury - which officers believe may have been caused by an air-gun.
A 24-year-old man and 23-year-old woman, who are not related to the child, have been arrested in connection with the incident.
Officers are continuing to investigate the events leading up to the incident, and forensic officers remain at the scene.
Detective Inspector Jonathan Deane said: "We believe the child received the severe injury from one pellet discharged from an air weapon. Our focus is very much on unravelling the full circumstances leading up to this tragedy.
"We're not looking for anyone else in connection with what happened and at the time we are treating this as a potentially negligent act."
Emergency crews were called to a flat in Bishport Avenue, Bristol, at 4.10pm on Friday. Neighbours reportedly said they heard the child "screaming and screaming".
The Bristol Post quoted an unnamed father, who witnessed the aftermath, as saying: "I couldn't sleep last night because I just couldn't get this picture out of my head. The mother was running behind covered in blood."
Police said the baby remains in a critical condition at Bristol Children's Hospital, and the boy's family were continuing to be given "all the help and support they need".
Officers have also thanked the local community for their patience and understanding while extensive inquiries have been carried out.
Mr Deane added: "Reassurance patrols will be carried out tonight and tomorrow. If any residents have specific concerns then please speak to their neighbourhood team."