Four teenagers are recovering in hospital after being shot in Merseyside on Saturday night.
Three 17-year-olds and a 15-year-old were injured in the same attack, which happened in Akenside Street, Bootle, at about 11.30pm.
Police have called the shooting "disgraceful", and say it is possible it may have been targeted.
Emergency services were called after reports that a 17-year-old youth had been shot, police said.
A short time later a 15-year-old youth and two 17-year-old youths sought medical attention for shotgun injuries believed to have happened in the same incident.
Their injuries are not thought to be life threatening.
A cordon has been put in place at the scene of the shooting and police are making door to door enquires and trawling CCTV footage from the area.
Chief Superintendent Julie Cooke, of Merseyside Police said: "This is a disgraceful act that has led to four young men receiving medical treatment for shotgun injuries.
"Although their injuries are not thought to be life threatening the consequences could have been much worse.
"We are currently keeping an open mind as to whether this attack was targeted."
She added: "The force, along with the community, will not tolerate the use of guns and the fear those who use them spread.
"I urge anyone who has any information that can help in our investigation to come forward."
Anyone with any information is asked to call Crimestoppers on 0800 555 111.