They said one of the wounded was in a life-threatening condition. Sky News quoted Gulled Bulhan, a 19-year-old student from Streatham, as saying he witnessed the shooting in front of a shop."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," Bulhan said."The man was then shot. I think I heard three gunshots but I can't quite remember."In one video of the scene posted on Twitter, but not verified by Reuters, a man can be seen lying on the street while at least two armed police officers point their guns from behind an unmarked car with its blue lights flashing.At least one helicopter flew overhead and police cars were in surrounding streets, with the area blocked off by tape.Prime Minister Boris Johnson said on Twitter: "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," he said.The last such incident in London was in November, when police shot dead a man wearing a fake suicide vest who stabbed two people to death and wounded three more before being wrestled to the ground by bystanders.That attack, at London Bridge, was carried out by a man with Islamist militant sympathies. He had been jailed for terrorism and released early.London's mayor, Sadiq Khan, said in a statement after Sunday's incident: "Terrorists seek to divide us and to destroy our way of life - here in London we will never let them succeed."Amman had been jailed for promoting violent Islamist material and had encouraged his girlfriend to behead her parents, it later emerged.In November 2018 he pleaded guilty to possession of terrorist documents and disseminating terrorist publications, and the following month he was sentenced to more than three years in prison.He was 17 and living at home with his mother and younger siblings when he first began committing terrorism offenses, according to authorities. Police became aware of his activities in April 2018 and he was arrested by armed officers in a north London street a month later.When officers examined his computers and phone, they found he had downloaded material about making explosives and carrying out terrorist attacks, according to police.Messages showed that he had discussed with his family, friends and girlfriend his extreme views and desire to carry out an attack, often focused on using a knife, police said.In December 2017 Amman posted a picture of Islamic State leader Abu Bakr al-Baghdadi, who was killed during a U.S. raid in Syria in October, and told his brother in a message that "the Islamic State is here to stay."He also described Yazidi women as slaves and said the Koran made it permissible to rape them, and in another message he encouraged his girlfriend to behead her parents.Police said he had shared an online al-Qaeda magazine with his family and while in a discussion about school with a sibling he wrote he would "rather blow myself up."#INCIDENT A man has been shot by armed officers in #Streatham. 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. Please follow @metpoliceuk for updates
— Metropolitan Police (@metpoliceuk) February 2, 2020