Police investigating the murder of County Monaghan teenager Jason McGovern in Omagh have arrested a fourth person.
It is believed the 19-year-old was punched at a pub on John Street on Sunday. He was hit a short time later at Cunningham Terrace car park and later died.
A 19-year-old man from the Omagh area was arrested yesterday evening. Hours earlier, police detained a 17-year-old boy from town.
Two others were arrested on Wednesday.
The men, aged 18 and 21, were also detained in Omagh and the teenager is still being questioned.
The 21-year-old has since been released on bail.
After being attacked, Mr McGovern made his way to a friend's house in Mullan village near Emyvale in County Monaghan where he was found dead on Monday.
A post mortem examination showed the teenager's death had been due to a head injury he suffered during the initial assault.