At around 11:45hrs on Monday, 4 September, police were called to reports of a man stabbed in Granby Terrace at the junction with Hampstead Road NW1.
Officers attended, along with the London Ambulance Service and a London’s Air Ambulance vehicle.
The man was pronounced dead at the scene. He is thought to be aged in his late teens or early 20s – urgent enquiries are underway to establish his identity and inform next of kin.
A 17-year-old youth has been arrested in connection with the investigation. He has been taken to a central London hospital; his condition is not believed to be serious.
Road closures are in place, and some train services have been disrupted while emergency services deal with the incident.
Enquiries continue to establish the full circumstances.