An 11-year-old child and a 30-year-old woman have been injured after a pellet gun was fired in south-west London.
Police said the child suffered a wound to her leg while the woman, who was known to the youngster but not related to her, suffered injuries to her back.
Both were taken to hospital for treatment, but neither is believed to have been seriously hurt.
Two men, both aged in their late teens, are also believed to have been hurt during the incident and went to a nearby hospital suffering shotgun pellet injuries which are not thought to be serious.
Officers were called to the scene in Figges Marsh, Mitcham, at 5.40pm on Sunday after reports of shots being fired.
Scotland Yard said a large group of men were seen in the area before the incident and police are trying to trace them.
The force said in a statement: "Detectives are urging anyone in this group who has not yet spoken with police to come forward."
No arrests have been made.
Anyone who witnessed the incident or has any information is asked to call 101.