Two children were injured in a shoot-out in the Moss Side district of Manchester, police said.
The armed police were called into Claremont Road around 2:30 am BST.
The police said the victims had done it "pellet-like wounds that are not believed to be serious". A man is in serious condition at the hospital with leg wounds.
Shooting took place at a street party held at Alexandra Park after the first day of the Caribbean Carnival this weekend.
Chief Supt Wasim Chaudhry of the Greater Manchester Police said: "Fortunately, the injuries suffered are not as serious as first thought and hopefully patients will leave the hospital during the day following treatment.
" It It may be that there are people who did not seek treatment last night, and I would urge these people to seek medical help immediately. "
He said the shooting was" a reckless act would have had devastating consequences.
The man in the hospital is said to be in a "heavy but stable state in the hospital."
It is not yet clear whether his injuries were caused solely by the pellets, the police said with] Caption [1
Moss Side Anti-Violence Fighter Erinma Bell told the BBC that she understands that the shooting was done by a man, but this has not been confirmed by the police.
The Caribbean Carnival, which has been held every summer since 1972, attracts thousands of people.
Residents said that after the first day of events, a street party was usually held in Claremont Road.
Youth worker Kemoy Walker, who had been on the main stage on Saturday, said he was shocked at the news.
He said he had been to another street party in Claremont Road until 11:30 pm.
"The party I was with was beautiful," he said.
"When I left, it was nice to dance, that's Moss Side, that's the culture, I'm in shock this morning."
He said He hoped the carnival would take place as planned on Sunday.
"We need to convey the message to young people that they are not involved in negativity," he said.
At the scene: Anna Jameson, BBC Radio Manchester
The Caribbean Carnival should be a festive event, especially on the occasion of the 70th anniversary of the arrival of the Windrush generation
Moss Side has done much in recent years to reinvent its image – in the past
The events overnight will be considered as absolutely shocking to the local community.
Officers will understand this and they will know that there will be many people who will be afraid in their own homes. Therefore, additional patrols will be carried out in the coming days.
Det Sup Debbie Dooley said, "The area is being searched and investigated, while we also try to talk to as many people as possible and to check CCTV get all the facts."
Additional officers will be in the coming days patrolling the area to reassure the public, she added.
Since the 1980s, the neighborhood has been associated with drug, gang and violence problems. 19659010] Image co Copyright
Former police officer Martin Harding, who now works with local schools, said the number of shootings has dropped significantly in recent years.
He said, "It's another sign of work in Moss Side – and neighboring Hulme – Works because it used to happen almost daily that similar incidents took place in the area."
He said the area have a "proud community" and that would be "many and many disappointments" at the last shoot.
He added, "The rest of the country will still remember the old bad headlines, but we know that is changing massively, and we know that massive investments have been made in the area – The Manchester Metropolitan University has
"We saw other companies moving back and saw that the area became a true international community."