Officers were called during the evening on Wednesday 2 June 2021 to a report of a disturbance involving a number of people in Dover Road near the junction with Harbour Way.
It was reported that an altercation arose in the street at around 8.10pm, between two groups of people, one group which was seen to have arrived in two cars.
Patrols and the South East Coast Ambulance Service attended the scene and a man was taken to a local hospital with an injury consistent with a stab wound.
A further two men also attended hospital for treatment to their injuries.
Detectives are working to establish the circumstances of the disturbance and have made a number of arrests in connection with it.
Four men from Folkestone, aged 18, 19, 41 and 51 were all arrested on suspicion of assault.
The 18-year-old was also arrested on suspicion of possessing cannabis.
The 41-year-old was further arrested on suspicion of violent disorder.
A fifth man from Folkestone, aged 21, was arrested on suspicion of perverting the course of justice.
They were all taken into custody.
Investigating officers are appealing for any witnesses, or anyone with personal CCTV in the area to come forward.
They would also like to hear from anyone who was travelling in the area between 8.10 and 8.15pm and has dashcam footage which could assist enquiries.
Witnesses should call Kent Police on 01843 222289 quoting 46/94657/21.