A man shot by police in what has been declared a terrorist-related incident in south London has died, Scotland Yard said.
The Metropolitan Police said the shooting occurred at around 2pm on Streatham High Road today.
The force believes there are also "two injured victims" from the incident and are awaiting updates on their condition.
In an earlier tweet, the Met said: "At this stage it is believed a number of people have been stabbed.
"The circumstances are being assessed; the incident has been declared as terrorist-related."
A 19-year-old student from Streatham, who did not want to be named, claimed to have witnessed the shooting on Streatham High Road in front of a Boots store.
He told the PA news agency: "I was crossing the road when I saw a man with a machete and silver canisters on his chest being chased by what I assume was an undercover police officer - as they were in civilian clothing.
"The man was then shot. I think I heard three gun shots but I can't quite remember.
"After that I ran into the library to get to safety.
"From the library I saw a load of ambulances and armed police officers arrive on the scene."
He said people began running into nearby stores after the incident.
"We were all informed to stay in buildings by armed police, until we were evacuated," he said.
It is understood people including children took shelter in nearby shops during the incident, with police later telling shops to close for the day.
Richard Mustonen-Smith, 59, a response pastor for Ascension Trust, has lived in the area all his life.
He told PA: "I'm shocked it's happened in Streatham. I've been here all my life. We're always getting accidents down here but not this.
"My grandson was in the Odeon and they got told to go out the back because there was a bomb. They got them to go out of the back of the cinema. They were there to watch a film.
"When it's a member of your family so close to you, you don't expect it. You're always worried about your family being on the streets but this is even worse.
"I heard two people got stabbed and apparently one man was shouting Allahu Akbar but people thought he was just a crazy man, so he got away. Apparently he had two rucksacks."
Commenting on the incident, London Mayor Sadiq Khan said: "I am in close contact with the Met Commissioner and local representatives, and want to thank our police, security and emergency services staff for their swift and courageous response. They truly are the best of us.
"Terrorists seek to divide us and to destroy our way of life - here in London we will never let them succeed."
Prime Minister Boris Johnson tweeted: "Thank you to all emergency services responding to the incident in Streatham, which the police have now declared as terrorism-related.
"My thoughts are with the injured and all those affected."
Home Secretary Priti Patel said on Twitter that she was being kept updated by police.
"My first thoughts are with the victims, our brave police and emergency services and their families," she wrote.