Gardaí a second man is helping them with their inquiries into a fatal attack on two Polish men in Dublin over the weekend.
A 19-year-old was arrested yesterday in connection with the attack and remains in garda custody this morning.
The two victims were stabbed in the head with a screwdriver during the attack on Benbulbin Road in Drimnagh on Saturday evening.
Gardaí upgraded their investigation to a murder inquiry last night after one of the men died in hospital as a result of his injuries.
The second man is in a critical condition.