A woman was stabbed to death in a busy shopping street after a knife was stolen from a local butcher's shop.
Another woman was slashed on the hand in the attack while a third has been arrested, Scotland Yard said.
An employee at The Rose pub in Broadway, Bexleyheath, south east London, said a blade had been taken from the British Meat Market ahead of the killing.
The woman, who did not give her name, said: "I didn't see what happened but I think one of the girls stole a knife from the butcher's.
"A policeman told my boss that's what happened. We were really shocked.
"On the whole we don't get that sort of thing around here. It isn't a bad place."
Police were called to the area at around 8.30am, along with London Ambulance Service.
The first victim, who was found with stab wounds, was pronounced dead at the scene at 8.41am.
A Metropolitan Police spokesman said: "We have recovered a knife from the scene. At this stage we are making inquiries as to where it came from."
Shop workers were forced to close their doors today as police sealed off part of the road to investigate the death.
A spokesman for London Ambulance Service said: "We were called just after 8.30am to reports of a stabbing on the Broadway, Bexleyheath.
"We sent an ambulance crew and an officer to the scene. Sadly one patient, a woman, was dead at the scene.
"A second patient was treated at the scene for a minor hand injury. She did not require hospital treatment."
Police have cordoned off the crime scene and forensic officers are on site.
A blue tarpaulin has been erected on Albion Road where the body was found.
The dead woman - who is believed to have been between 40 and 50 - has not been formally identified. Her next of kin have been informed.
Officers said it was too early to determine a motive for the killing.
Anyone with information is asked to call police on 020 8721 4805 or contact Crimestoppers on 0800 555 111.
Josh Williams, 16, a shop assistant at Jaley's Smoothies, Milkshakes & Ice Creams, said he had spoken to a customer at 8.45am who witnessed the aftermath of the stabbing.
He said: "The man said the girl's friend was walking down to the petrol garage and her arm was covered in blood and he said 'Oh, what's going on here?' and two of the girl's friends just broke down in tears and said 'Her friend's been stabbed'.
"He said they were schoolgirls wearing a grey uniform."
A traffic warden said he had seen a "scuffle" break out in front of the Snappy Snaps photographic shop, close to an Asda store and a short distance up the road from the British Meat Market.
"We saw three girls involved in a scuffle," he said.
"Then I saw one of them had a knife and then she dropped it and started walking down Broadway."
A shopkeeper said he saw a "young woman" walk into the butcher's shop.
"She threatened the shop manager there and took a knife," he said.
"After that she ran down Broadway towards Albion Road."
The suspect was taken to hospital following the attacks. It is not known whether she suffered any injuries.
Medical staff are now understood to be assessing her for mental health problems.
Scotland Yard said both victims were adults.