Police are investigating the death of a man who suffered a fatal stab wound in a confrontation with three youths.
The victim, whose name has not been released, was injured outside his home in Partick Road, Sunderland, and later died in hospital.
His death is being treated as murder, and police believe it may be linked to a further stabbing just minutes later.
It happened in nearby Galway Square, when a man was approached by three youths and stabbed in the chest.
He is being treated in hospital but his injury is not life-threatening.
There were also reports of youths causing a disturbance in the area between the two incidents, early on Saturday morning.
Police are speaking to witnesses and establishing descriptions of those involved.
DCI Roger Ford, who is leading the murder investigation, said: "There were a number of incidents in a relatively short space of time and we are appealing for anyone who saw or heard anything or has any information, to come forward."