The PSNI are appealing to anyone who may have witnessed a robbery in the city on Thursday night past to contact them with any information.
The incident took place in the Foyle Road area on Thursday past, just before 11:30pm when a man in his 30s was robbed and assaulted.
The man was later taken to hospital where he was treated for injuries which are not thought to be life threatening.
A 36-year-old man and a 24-year-old woman were arrested in connection but have since been released on bail pending further police enquiries.
Police are asking anyone who witnessed the robbery or has any information is asked to contact Detectives at Reactive and Organised Crime at Strand Road Police Station or anonymously contact Crimestoppers.