Police are searching for a man who is believed to have suffered a stab wound to his arm after a disturbance in Hudson Street in Bicester on Saturday morning.
Police were called to Hudson Street, Highfield, at around 9.25am after reports that a man had been stabbed in the arm.
Officers are trying to trace the victim, who is around 18 years old, of medium height and slightly built. He had short dark hair and was wearing a T-shirt and dark trousers.
Anyone with information about the victim or the assault is asked to contact investigator Mark Doran on the non-emergency number 101.
Details can also be left with the independent charity Crimestoppers anonymously on 0800 555 111 or online at www.crimestoppers-uk.org.