A 17-year-old boy has been arrested on suspicion of murdering a man who died after being stabbed.
Police were called to Stourbridge Common in Cambridge at about 16:15 BST on Wednesday and found a seriously injured man nearby in Ditton Walk.
The victim, in his 40s, died later at Addenbrooke's Hospital.
A 17-year-old boy who was arrested earlier remains in custody. Police are treating the death as an isolated incident.
Det Ch Insp Mike Branston appealed for information and said the scene remains cordoned off and extra officers are patrolling the area in the east of the city.