Patrols were called at 12.26am on Saturday 1 January 2022 to a report of an assault in Sandgate Road where a 17-year-old boy had suffered an injury consistent with a stab wound.
He was taken to a London hospital for treatment.
A 17-year-old boy from Folkestone was arrested on suspicion of Grievous Bodily Harm. He has been released on bail, pending further enquiries, until 24 January.
Enquiries into this incident are ongoing and anyone with information is urged to call the appeal line on 01843 222289 quoting reference 01-0071.
You can also call the independent charity Crimestoppers anonymously on 0800 555111 or complete the online form at www.crimestoppers-uk.org.