A 20-year-old man has been arrested by detectives investigating the murder of 14-year-old Martin Dinnegan in London.
Martin was stabbed to death on Tuesday night in Islington, north London, after he and his friends became involved in an argument with a group of up to 20 youths.
Police were also continuing to question a 15-year-old who was arrested on Wednesday night in connection with the murder and is being held in custody at a London police station.
Martin's father, 42-year-old James Dinnegan, is originally from Mullingar, Co Westmeath.
