A murder investigation has been launched after a woman was stabbed to death in south London.
Officers were called to Frith Road in Croydon, at 9.07am on Saturday, the Metropolitan police said.
The London ambulance service and London’s air ambulance treated two injured people.
The woman, who is in her 20s, died at the scene, despite the efforts of a teenage boy to help her, police said.
A man in his 30s was taken to hospital with minor injuries. He has since been arrested on suspicion of murder and remains in hospital, Scotland Yard said.
Initial inquiries suggest the incident started at a nearby address, before escalating on to Frith Road, the force added.
Supt Mitch Carr said: “This is a tragic incident where a young woman has lost her life and our thoughts are with her loved ones.
“I especially want to thank the members of the public, including a teenage boy, who bravely tried to help the victim.
“We believe that this was an isolated incident, but understand that this news will shock the local community. Officers will remain in the area over the coming days and we would ask anyone who has concerns to speak with them.”