Police questioning two people after a man was murdered in Co Londonderry last night appealed for help from witnesses who came to the victim's aid.
The 28-year-old man was attacked on the Promenade of the coastal town of Portstewart at 2am yesterday after leaving the Havana nightclub, part of Shenanigans bar, where an earlier dispute is believed to have taken place.
A 20-year-old man and a 31-year-old man are being questioned by police.
The victim, named by police as Trevor Spiers, was taken to hospital where he died a short time later. Police now want to speak to bystanders who came to the injured man's aid after the assault.
SDLP East Derry Assembly Member John Dallat said: "I was in Portstewart last night a couple of hours before this death and no-one could have predicted that someone would lose their life later in the evening.
"Taxis were going about taking young people to various places of entertainment and the town was very peaceful.
"It is hard to take that a young man would later be dead and a family plunged into mourning.
"I have spoken to the police this morning and they are doing everything possible to establish what led up to this unfortunate incident, and I would ask anyone who knows anything about the circumstances to get in touch with the PSNI (Police Service of Northern Ireland) immediately."
He added: "My immediate thoughts are with the family of the deceased. This is so tragic, particularly in the run-up to Christmas, which is traditionally a period of joy and happiness."
The victim had been in the Havana nightclub, above the Shenanigans bar in the seaside town, which is a popular nightspot close to the University of Ulster campus at Coleraine.
Politicians said the wider drinking culture in towns and cities across Northern Ireland had to be tackled.
Sinn Fein representative Billy Leonard blamed a culture of aggression for such violence.
"Obviously my first thoughts are with the family circle of the young man who has lost his life - they are bound to be totally devastated," he said.
"Their son goes out to enjoy himself and he doesn't return home. It is totally sickening to think of."
He added: "There have been too many incidents of fights and attacks in and around nightclubs, not only in our area but elsewhere.
"The culture of aggression is ever-present and unfortunately it has now gone to the sickening level of this person's death."