Four teenagers have been arrested after a CCTV operator saw a large knife being pulled from a rucksack by a boy on the seafront.
It happened in front of St Mary in the Castle, around 5.15pm on Thursday (March 24).
An argument ensued involving the boy and a number of other young people, before some of the group broke off and ran from the area.
Police arrived at the scene and arrested a boy on suspicion of being in possession of a knife in a public place and affray - he was later charged for the knife offence, but cannot be named for legal reasons.
No knife was found during the arrest and so a Section 60 order was authorised, which allowed officers to stop and search people, in order to find the weapon.
Searches found two lock knives and bags of Class B drugs. Three other boys were arrested on suspicion of offences including possessing a knife in a public place; affray; and possession with intent to supply a controlled Class B drug.
Searches were then conducted at an associated address and further drugs and weapons were found and seized.
The other three boys have been released under investigation while enquiries continue.
Detective Sergeant Daniel Beek said:
"Thanks to the vigilance of a police CCTV operator, officers were able to quickly respond to reports of a knife in the town centre and disrupt a group of people involved in an altercation.
"Knife crime, violence and anti-social behaviour has no place in our community and when we become aware of incidents like this, we will use the policing powers available to us to address it. Sometimes that's a dispersal order or like in this instance, a Section 60 order allowing stop and search.
"This proved effective in allowing us to search for harmful weapons and drugs, and was done with the purpose of protecting people from harm, keeping our communities safe and identifying those intent on committing offences.
"This altercation happened in a busy tourist location on a sunny day, and we understand it may have caused distress for those who were in the area at the time. We hope our robust response provides some reassurance that we take reports of this nature very seriously and will respond appropriately.
"We continue to ask anyone who did see what happened to contact us if they have any information which could assist with the ongoing investigation."
Anyone with information can contact police online or by calling 101 quoting serial 961 of 24/03. Alternatively, you can contact the independent charity Crimestoppers anonymously on 0800 555 111.
Man Charged After Throwing Brick Through Brighton Restaurant Window
Peacehaven Man Disqualified Over High-Speed A27 Pursuit Near Brighton
Appeal After PCSO Assaulted In Uckfield
Man Charged With Rape Of Teenage Girl In Newhaven
Overnight Closures For A22 Forest Row Road Improvements
Brighton Defence Manufacturer's Controversial Planning Application Likely To Be Heard
Over £2.4m Approved For Worthing School Support Centre
Section Of M25 To Close Again Tonight - As Drivers Warned Not To Get Complacent
Plans For 800 New Horsham Homes Refused
Over 200 Co-Living Flats Approved For Brighton