A shotgun was fired "recklessly" at least twice into a large crowd of people at a Manchester street party following the city's Caribbean Carnival, police believe.
Detectives say the answers to Sunday's shooting which injured 12 people, including a 12-year-old girl, may lie within the Moss Side community as they explore a "number of working hypotheses for the motive".
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Two men, aged 23 and 30, and the young girl remain in hospital for treatment for injuries that are not believed to be life-threatening.
Officers were called to reports of gunshots in Claremont Road at about 2.30am and armed and unarmed officers arrived one minute later with several people having suffered pellet injuries.
Chief Superintendent Wasim Chaudhry, of Greater Manchester Police, said: "We are now more than 24 hours on from this truly shocking attack and our investigation team has been following numerous lines of inquiry in their attempts to establish the full picture of what happened.
"A key part of that work to establish the full picture is information from the community being fed into the investigation team by members of the public.
"The person responsible for this incident recklessly fired a gun into a crowd of people enjoying a celebration of Caribbean culture, which included children.
"One of those injured by the shooting was a 12-year-old girl who remains in hospital with her family at her bedside but thankfully she should make a full recovery.
"We need to get answers for her family and the loved ones of all the people injured in the incident and we believe those answers may lie within the community.
"I want to urge anyone who thinks they may know anything to please get in touch as a matter of urgency.
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"If people don't feel comfortable contacting the police then people can report information anonymously to Crimestoppers, which is a charity that is completely independent from the police."
The weapon believed to have been used in the attack has yet to be recovered.