A teenage boy is in hospital after being stabbed at Cubbins Green in Caldy.
The incident happened at around 7pm on Friday evening.
He was taken to hospital with stab wounds to his legs, and is in a stable condition.
Armed police were drafted in to search for the suspect.
Merseyside Police Chief Inspector Lisa Ledder said: “We are in the early stages of an investigation into a stabbing which has left a teenage boy injured.
“Armed police patrols remain in the area as a precaution, and I would appeal to anyone who was on Cubbins Green at around 7pm onwards and saw what happened to please contact us.
“We understand the area was busy with several groups of teenagers and I would ask those people to come forward if they have any information that could help us find those responsible. Similarly, if you were in the area and have dashcam or CCTV footage please check your systems just in case they may have captured something which may be vital to our investigations.
“Our officers will immediately respond to any knife crime incidents and are committed in removing anyone who stores, carries and uses weapons through proactive use of stop and search powers, open land searches, warrants and education work alongside partners.
“A young person who carries a knife may be throwing away their life or destroying others and we will continue to seek out those that cause harm and fear in our community.”
Anyone with information is asked to call 101, DM @MerPolCC or @CrimestoppersUK on 0800 555 111 quoting log
1117 of Friday 16 June.