Violent incident also saw two police officers injured by the armed assailant.
ADVERTISEMENTA sword-wielding man attacked police and members of the public in London on Tuesday, killing a 13-year-old boy and injuring four others.
Police say the incident in the east London area of Hainault is not being treated as terror-related.
Police were alerted to the incident by reports of a man driving a vehicle into a house on a residential street, and of people being stabbed at a nearby underground station. Two police officers were amongst the wounded.
A 36-year-old man was arrested at the scene. Police say they do not believe there is a threat to the wider community.
"I cannot even begin to imagine how those affected must be feeling," said Chief Superintendent Stuart Bell, describing the incident as "truly horrific".
Video on British media showed a man in a yellow hoodie holding a long sword or knife walking near houses in the area.
Witnesses say they heard police shouting to the suspect urging him to put down the weapon as they chased after him.