Three people were arrested after a man was assaulted in a house in the Cable Street area of the Bogside on Monday evening.
Shortly before 6:55pm, it was reported a 47 year old man was assaulted in a house in the area.
It is believed the man received facial injuries and was taken to a hospital for treatment, the PSNI said.
A 28 year old man was arrested in relation to the incident and is currently helping police with their enquiries.
Two women aged 38 years old and 31 years old, who were in the property during the incident were also arrested.
Police would ask anyone who may have witnessed this incident or who has any information to contact them at Strand Road on 0845 600 8000.
Or, if someone would prefer to provide information without giving their details they can contact the independent charity Crimestoppers and speak to them anonymously on 0800 555 111.