A 60-year-old man has died after being stabbed in a "random and unprovoked assault" in central London in broad daylight.
Police have started a murder investigation into the “unprovoked assault” which unfolded in Oxford Circus on Thursday evening.
A 25-year-old man was arrested at the scene on suspicion of grievous bodily harm and possession of an offensive weapon.
He was subsequently arrested on suspicion of murder and remains in custody at a central London police station.
A witness said a member of the public had jumped on the suspect before others pinned him down near the Nike Town store in Oxford Street.
Detective Chief Inspector Vicky Tunstall, from the Specialist Crime Command, said: “This is being treated as a random and unprovoked assault and we are not actively looking for anybody else in connection with the incident. I would like to reassure the public that this is not believed to be linked to terrorism.
“It is clear that this area of Oxford Circus was very busy at the time of the attack. Members of the public intervened to detain the suspect and I hope to trace and speak to them, to secure their accounts and offer support. In particular, I would like to trace two young males with skateboards who led this intervention.
“I am appealing to any person who witnessed the assault, or who has mobile phone footage, to contact us. I am also appealing to the owners of any passing cars with dashcams to check whether they have recorded the incident.”
Police were called just before 8pm to reports of a stabbing and an air ambulance was scrambled to the scene on the corner of Regent’s Street.
Officers and paramedics treated the victim there before he was transferred to a central London hospital but later he died.
Several people have taken to social media to describe the distressing scenes.
One person posted on Twitter: “Oxford Circus locked off due to stabbing.”
“A middle aged gentleman who just got stabbed in Oxford Street looks ok. Hopefully he fully recovers,” said a second witness.
A crime scene was in place on Friday morning with officers remaining in the area.
Detectives are trawling for CCTV which could have caught the incident.
Anyone who witnessed the assault, or who captured it on mobile phone, is asked to contact police via 101 quoting reference Cad 7129/01Jul.
Alternatively, to remain anonymous, call Crimestoppers on 0800 555 111.