A man is seriously ill in hospital and another suffered serious injuries in a stabbing in Stanground on Saturday night.
The incident happened in Southfields Avenue on Saturday night.
A Cambridgeshire police spokesman said: “We were called by the ambulance service at about 9.15pm on Saturday to reports of a stabbing at a property in Southfields Avenue, Peterborough.
“At least one man suffered serious injuries and was treated in hospital.”
The spokesman said one man remained in hospital, while a second man, who also suffered serious injuries, had been discharged. Both men are aged in their 20s.
Detectives have now released descriptions of three men they want to trace in connection with the incident.
The first is described as white, aged 27-30, tall (about six foot), short black hair, white shorts, yellow t-shirt, clean shaven but possibly with a thin moustache.
The second is white, tall (about six foot), short black hair, clean shaven and wearing a grey tracksuit.
The third man is described as being white, 27-30, shorter than the other two, shaved head, clean shaven, wearing a black jacket and trousers, possibly jeans.
The police spokesman said the stabbing was being treated as an isolated incident.
Anyone with information should contact DC Aaz Tourabi, at Thorpe Wood Police Station, on 101 or Crimestoppers, anonymously, on 0800 555111.