At around 12.36pm on Thursday officers were called to Station Road, Slough, following reports of an altercation.
An 18-year-old man sustained wounds to his back and hand and has been taken to hospital where he remains.
An 18-year-old man from Slough has been arrested on suspicion of section 18 grievous bodily harm and is in police custody.
As a result of this, Thames Valley Police has authorised extra search powers under Section 60 of the Criminal Justice Public Order Act 1994
Investigating officer Detective Sergeant Georgina Adey, based at Slough police station, said: “I am appealing for any witnesses to this incident, or anyone who has any information to please come forward.
“Further, if any motorists were in the local area around the time of this incident, I would urge them to check any dash-cam footage in case it may have captured something that could assist with the investigation.
“Anyone with information is asked to call 101 or make a report online, quoting reference 43200361023.
“Alternatively, if you wish to remain anonymous you can contact the independent charity Crimestoppers on 0800 555 111.”