More than 100 knives have been handed into Derbyshire police during the first two weeks of an amnesty.
Police have also arrested five people in incidents across the city after they were found carrying knives.
The amnesty was organised by Operation Redshank, a specialist team set up to tackle gang crime in the city, and was supported by Derby County Football Club.
Superintendent Gary Parkin, head of operations for Derby division, said: “The aim of the amnesty was to stop knives and other weapons from falling into the wrong hands and ultimately, to make the streets of Derby safer. Every knife handed in is one less that can potentially be used in the city.”
Supt Parkin said that several of the weapons handed in were homemade, improvised knives. He added: “Weapons such as these can only have been made for one thing – for use in crime. There is no other reason for creating make-shift knives like the ones we have had handed in this month.”
