An elderly man riding a mobility scooter in west London has been stabbed to death.
Police were called on Tuesday afternoon to Cayton Road, Greenford and despite the efforts of paramedics he died at the scene.
The man is believed to have been in his 80s and police are in the process of letting his family know about the attack.
No one has been arrested so far.
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 dashcam 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 3.15pm and 4pm.
“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.”
Simran Advani, 25, a senior property manager who lives near to where the stabbing took place, said she often saw an elderly man on his mobility scooter who “always used to smile”.
She said: “He was a nice old man. He often goes round the block, he always went on the road not the pavement.”
She added: “This is a very quiet area, you never hear any noise on this street. It’s scary for a man in his 80s to be killed here. Most people on this road are elderly, you never hear any noise and never see any young people.”
Forensic experts in blue overalls could be seen loading bags containing various items into police vans as dozens of officers guarded the scene.
A police cordon had been thrown over the site of residential semi-detached houses. It covers a T-junction between Cayton Road and Runnymede Gardens, which runs parallel to the busy A40.
Frasley Coutinho, who lives opposite the scene of the attack said he saw the victim surrounded by a group of young boys.
He said: “I saw a couple of people gathering around him and then he drove past and stopped further up, and then there was a group of young boys around him.”
Mr Coutinho said he caught some of the incident on a CCTV camera but it was obscured by a plant.
“I had a rose plant blocking it so I couldn’t see any more,” he said.
Two blue, yellow and white crime scene tents marked “MPS” were pitched up next to the A40 on Runnymede Gardens, where forensic officers were working under bright lights on the road surface.
Another neighbour, who did not wish to give his name, said: “It’s not nice, it’s normally quiet here. It’s out of the way.
“I feel sorry for his family – I’m not entirely shocked with the amount of stabbing you hear on the news.
“There are not many people coming and going, there’s not really any foot traffic. There’s playing fields and a school nearby. A lot of people park their cars here.”
He said there was a bus stop nearby, but “other than that not many people are walking around here”.
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.”
So far this year there have been 58 homicides in London.
Want a quick and expert briefing on the biggest news stories? Listen to our latest podcasts to find out What You Need To Know...