A man has been stabbed to death in Londonderry.
The 35-year-old was attacked during the early hours of Sunday morning following an "altercation" involving a number of men in the Grafton Street area, the PSNI said.
Three men, aged 19, 20 and 27, have been arrested and are in custody assisting police with their murder investigation.
Detective Chief Inspector Alan Dickson, from PSNI Major Investigation Team, said: "We are working to establish the circumstances of this incident and determine the precise sequence of events that culminated in the tragic death of this man.
"I would appeal to anyone who was in the Grafton Street or Park Avenue areas of Derry this morning between 2.30am and 3am to please get in touch."