The Northern Ireland Police Ombudsperson, Nuala O’Loan, is investigating the circumstances in which two officers were injured - neither seriously - and a shot discharged during a disturbance in West Belfast early this morning.
Four people, two men and two women, are still in police custody following the incident.
It happened when officers responded to reports of a serious fight between a number of people armed with knives in the Kelly's Corner area of the city.
Three other people were taken to hospital with head injuries, one is said to be in a critical but stable condition.
It is believed that a hammer was used in the attacks.