Police stopped 88 people during a weapon and drugs crackdown at Crystal Palace train station.
Operation Dracula saw Bromley officers working alongside British Transport Police to target people coming into the borough with drugs or weapons.
Three men were arrested after drugs dogs detected they were carrying illegal substances.
They included a 34-year-old jobless man from Tunbridge Wells who was cautioned for cocaine possession.
Two 19-year-old men, one from Southwark and one from East Dulwich, were both given a caution for possession of cannabis.
A 35-year-old man from Brixton was arrested and handed over to Lambeth police as he was wanted in the borough on suspicion of common assault.
Also arrested were a 25-year-old financial insurance broker from Sheffield who was cautioned for possession of an offensive weapon and possession of cannabis and a 16-year-old boy from West Norwood.
The teenager was bailed to return to Bromley police station on August 6 after being arrested for a public order offence.
Officers also issued five people with cannabis warning forms, three people were given a penalty notice for possession of cannabis and one person was issued with a penalty notice for fare evasion.
The operation took place between 3.15pm and 7pm on July 6.
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