Two men followed a group of two other men and two women from the Xscape Milton Keynes building into a car park on Avebury Boulevard
An altercation then took place where one of the women was pushed over.
She broke her ankle as a result of the fall, and one of the men suffered a facial injury that required stitching.
The woman was taken to Milton Keynes General Hospital where she received surgery on her ankle.
She has since been discharged.
Investigating officer Detective Constable James Day, of Milton Keynes station, said: “We are appealing for anyone who may have information regarding this incident.
“We are trying to establish the circumstances of this incident, so anyone with any information that could help us is encouraged to get in touch.”
Anyone with information is asked to call 101 quoting 43180289781
