LONDON - London's Metropolitan Police said it is investigating a terror-related incident after "a number of people" were stabbed and officers shot a man Sunday.
The police force said the incident happened in the London's Streatham neighborhood.
The Metropolitan Police tweeted details of the incident on Sunday afternoon, saying "The circumstances are being assessed; the incident has been declared as terrorist-related."
The BBC said that witnesses reported hearing two gunshots just after 2 p.m. on Sunday.
Social media showed multiple ambulances on the scene and helicopters in the air as helicopters responded to the incident.
Police warned people to stay out of the south London neighborhood.
Gulled Bulhan, a 19-year-old student from Streatham, told Britain's Press Association that he witnessed the attack.
"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," he said. "The man was then shot. I think I heard three gun shots but I can't quite remember."
Bulhan said he ran into a local library to seek safety.
"From the library I saw a load of ambulances and armed police officers arrive on the scene," he said.
Police say at least three people were injured in the stabbings.
This is a developing story. Check back later for updates.