Officers and the South East Coast Ambulance Service attended and a man in his 20s received medical attention and was then airlifted to a London hospital, where his condition is described as serious but stable.
An investigation has been launched and initial enquiries are being made in the area into the circumstances surrounding the incident.
Anyone with information is asked to contact officers on 01843 222289 quoting reference number 29-1267.
Alternatively, you can call the independent charity Crimestoppers in Kent, anonymously, on 0800 555111.