The performing arts school which counts Adele and Amy Winehouse among its former pupils has stepped up security after a number of students were mugged.
Police have upped patrols near the Brit School in Selhurst, Croydon, following a rise in crime over the past month.
Members of staff have also been made available to escort groups to the station in the evening and students have been warned to be on their guard.
Four youths have been arrested in connection with the muggings.
Detective Inspector Brian Hobbs, of Croydon Police, said mobile phones in particular were being stolen.
He added: “There may be a number of offences that have gone unreported.”
A school spokeswoman said: “It is paramount that our students feel safe.
“We have made staff available to walk groups to the station in the evening, increased staff presence in the local streets at lunch time and after school.”
About 900 pupils aged 14-19 attend the school, which is the only free performing arts and technology institution in Britain.
Other alumni include singers Kate Nash, Katie Melua, Leona Lewis and Jessie J.
