An elderly man on a mobility scooter was stabbed and killed as police appeal for witnesses.
The Met Police were called shortly after 4pm on Tuesday, August 16, in Greenford, west London, where the victim, believed to be in his 80s, was found.
Paramedics pronounced the man dead at the scene off Western Avenue A40 Eastbound.
No arrests have been made yet.
The force has urged anybody with information about the incident to come forward.
Images from the scene show the cordon, as well as the man’s mobility scooter and emergency staff and vehicles.
A witness told the Mirror the scene was “chaos” as police went door to door gathering information.
He said: “There was about eight or 10 coppers all milling around outside a house.
“There were coppers going door to door on the other side of the dual carriageway.
“There was coppers in the shops round the corner, a hell of a lot of coppers everywhere.”
He went on to say the footbridge going over the A40 had been shut off, adding: “It’s pretty horrendous.”
Detective Chief Inspector Jim Eastwood from the Met’s Specialist Crime Command said: “My officers are working to understand what has happened to this man, and we need the public’s assistance.
“I’m asking for anyone with dash cam or cycle helmet footage to contact us if they were using the Western Avenue A40 Eastbound in the proximity of Cayton Road and Welland Gardens between 15:15hrs and 16:15hrs.
“The elderly victim, who was riding a mobility scooter, was in the area at the time. If you saw the victim, or captured anyone acting suspiciously in the area, it is imperative that you make contact.”
Chief Superintendent Sean Wilson, lead for policing in Ealing, said: “This is an awful incident that will understandably cause considerable alarm to people locally and across London.
“Our thoughts are with the elderly victim.
“We are supporting our colleagues in Specialist Crime as they work to understand what has happened and identify who is responsible for this horrific crime.
“The support of the public is crucial. Police and the community must work together to identify violent offenders and remove them from our streets.
“My officers will remain on scene. They are there to help and protect you – if you have information that you want to share please approach them and tell them what you know,” he added.
London Ambulance Service said: “We were called today (August 16) at 4.10pm to reports of an incident at Runnymead Gardens, Greenford.
“We sent a number of resources to the scene, including an ambulance crew, a medic in a fast response car and an incident response officer.
“We also dispatched London’s Air Ambulance. Sadly, despite the best efforts of our crews, a person was pronounced dead at the scene.”
Mayor of London Sadiq Khan tweeted: “I’m devastated that an elderly man was killed in a horrific attack this evening. My thoughts are with the victim’s loved ones.
“I’m in close contact with @MetPoliceUK who have an additional uniformed presence in the area. I urge anyone with information to come forward.”