An 18-year-old man has been arrested on suspicion of the murder of a young man who died in Londonderry city centre.
The 19-year-old victim has been named as Jordan McConomy from the Rossnagalliagh area of the city.
It is believed he was assaulted in the William Street area at around 2.15am on Sunday.
The suspect is being questioned at Strand Road PSNI Station.
Police are continuing to appeal for people who were in the area at the time to come forward with any information.
Detective Chief Inspector Geoff Boyce said: “We know that many people were socialising in William Street early this morning and we would like to hear from members of the public who witnessed an altercation in the area between approximately 1:45am and a 2:15am to get in touch with detectives at Strand Road on telephone number 101, quoting reference number 228 of 24/9/17.
“Police would particularly like to hear from motorists who were either parked on or travelling along William Street during these times and who had a dash cam fitted to their vehicle.
“Alternatively, information can also be given anonymously through the independent charity Crimestoppers on 0800 555 111.”