A £1,000 reward is being offered for information after a teenager was stabbed in Ewell.
Eleven men, all in their teens or early 20s, have now been arrested in connection with the attack.
The 15-year-old boy was stabbed during a fight between a large number of youths, who are believed to know each other, in the Watersedge area of Ewell at 7.30pm on November 11.
The victim was taken to hospital for treatment to a number of stab wounds but his condition was not life threatening.
Seven of the men have been arrested for attempted murder, two on suspicion of perverting the course of justice, one on suspicion of public order, and one on suspicion of theft of motor vehicle.
They have all been released on bail until December 13, while the investigation continues.
Crimestoppers is offering £1,000 for people who want to provide information anonymously which leads to the arrest and charge of at least one person in connection with this incident. Information passed to the police will not qualify.
Detective Inspector Sean Kelly said: "I hope the number of people we have arrested so far in this investigation goes some way to demonstrate to the local community our commitment to keeping the streets of Surrey safe.
"I would strongly urge anyone who was involved in the incident in any way on Monday night to contact us if we have not already spoken to you.
“We simply will not tolerate behaviour of this nature in our county and further arrests are planned.
"Although the victim suffered serious injuries, thankfully they were not life threatening, this could have been a lot different, stab wounds can kill and those involved in this altercation need to be reminded of the dangers they are putting themselves and others in by carrying weapons.
"This was a rare and isolated incident for Ewell in which the offenders and the victim are believed to be known to each other.
“Detectives are working closely with the Epsom and Ewell safer neighbourhood team in the area following the disturbance to reassure the community.”
Detectives investigating the incident have now launched a website where people can upload images or footage of the incident to assist with the investigation, details of which can be found by clicking here
Contact Crimestoppers anonymously on 0800 555 111. If you have any information call the police on 101 quoting reference EP/13/4709.
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