A 14-year-old boy has been arrested on suspicion of murder following the death of a 47-year-old man.
Durham Police said officers were called to reports of an altercation in Southernwood, Consett, just before 5.33pm on Thursday in which the man had suffered a serious injury.
A force spokesman said that although doctors and paramedics attended the scene, he was pronounced dead a short time later.
The teenage boy has since been arrested on suspicion of murder in connection with the incident and is currently in police custody, the spokesman added.
Detective Superintendent Dave Ashton said: “This is a tragic incident for all involved, and I would like to offer my condolences to the victim’s family.
“I would like to reassure the local community that we are not looking for anybody else in connection with this incident.
“We have a dedicated team of officers and staff who have been working around the clock to establish exactly what happened.”
A unicorn garden ornament and some tarpaulin could be seen in a cordoned-off section of the road which was guarded by police, although these were not thought to have been used in the alleged murder.
The incident happened on a modern housing estate, close to Consett town centre, surrounded by more traditional terraced houses.
Durham Police said the victim, who lived locally, did not know the arrested boy.
Bouquets of flowers have been left beside the police cordon.