Police were last night questioning a man in connection with the stabbing to death of a 16-year-old youth in Portadown, Co Armagh.
The victim, named yesterday as Mr Samuel Killops from Festival Road, died after he was attacked with a knife in the Carlton Street and Meadow Lane area in the town centre shortly before midnight on Saturday. He died later in hospital.
Police also said they were examining a passport in connection with the murder, leading to speculation concerning involvement by someone from overseas. Police said they are not treating the incident as sectarian.
It was reported that the dead youth was involved in an incident in the same area in recent weeks.
Unionists and the SDLP condemned the murder.
Mr George Savage, a UUP councillor, said: "This is utterly despicable. This is a terrible thing to happen during the festive season." Ms Dolores Kelly, a former SDLP mayor in the town, added: "I am absolutely stunned and horrified that a young man has lost his life in such absolutely tragic circumstances. My heart and sympathies go out to his family circle. It is absolutely horrific that at any time a young person dies so brutally, but especially at Christmas time."
In Belfast, detectives have made fresh appeals for information concerning the murder of Mr David Cupples, who died on Christmas Day following a severe beating in north Belfast.
Mr Cupples (25), from the Braniel estate in the east of the city, was walking to Girdwood British army base in the area when he was attacked, receiving fatal head injuries.
Police yesterday handed out leaflets calling for anyone with information to come forward. It is thought an instrument was used to kill the civilian worker. Two men, both 20, are helping detectives with their inquiries.
Police said at the time of the murder they could see no obvious motive, but it is thought he may have been mistaken for a Catholic.
In another incident yesterday, a man escaped uninjured after shots were fired at his home in Dunraven Park in the Strandtown area of east Belfast. His attackers opened fire on his home where he was alone at about 1 a.m. yesterday.
The PSNI is discounting talk the gun attack is connected to feuding between loyalists factions within the UDA, which has claimed three lives since the autumn.