A man is to be reported to the Public Prosecution Service after cannabis and diazepam tablets were seized in the Shantallow area on Tuesday.
In another search, a man was arrested on suspicion of being concerned in the supply of a Class B drug and possessing it with intent to supply.
On Tuesday night, a man was arrested in Union Place on suspicion of possession of Class A and Class B drugs.
Three men have been arrested in Londonderry for drugs offences.