The PSNI are continuing to investigate the death of a man in Co Tyrone at the weekend.
It came after what police described as an "incident involving a man armed with a machete" in Omagh last night.
A man aged 53 died later. However, it is not believed that he died as a result of a machete attack.
A post-mortem examination is set to take place tomorrow to determine the cause of his death.
Detective Chief Inspector John Caldwell said a 20-year-old man was arrested on suspicion of murder.
"We received a report at around 11.55pm about an incident involving a man armed with a machete outside a house in the Slievecoole Park area of the town," he said.
"Officers attended, along with colleagues from the Northern Ireland Ambulance Service. Sadly, one of the men, aged 53, who had been administering first aid, died a short time later. Another man was taken to hospital for treatment of injuries to his hand.
"A 20-year-old man has been arrested on suspicion of murder and attempted murder, and is currently in police custody."
The PSNI have appealed to the public, particularly from anyone who was in the Slievecoole Park area or licensed premises in the Gortin Road area yesterday around the time the assault was reported and who saw what happened, to get in touch.
