A man has died after being attacked with an axe in a wealthy London suburb.
The victim had suffered serious head injuries
Officers found a man, armed with an axe or hatchet, standing over a body in Eton Avenue, Swiss Cottage, north-west London, at about 0940 GMT on Monday.
Police said the victim, a 67-year-old man who lived locally, had suffered severe head injuries.
Detectives say it is unlikely to have been a random incident. A 37-year-old man from the Camden area was arrested near the scene of the attack.
Police said they are trying to establish if the men knew each other.
Witness Margaret Mikkelsen said people confronted a man who was standing holding an axe while another man was lying face down on the floor.
"A man who lives in my building was telling him to put the axe down then two men grabbed scaffolding poles to try to stop him hurting anyone else," she said.
People were shouting at him to put the axe down but he only responded when the police arrived, she added.
Eton Avenue remained closed for the rest of the day as forensic experts carried out examinations.
Scotland Yard said they were called to reports of a "serious assault in progress" and found the victim who was already dead.