Parts of central London are on lockdown, and police are treating the incident as a terror attack.
A person is believed to have started attacking people with a knife and was then shot by police on the north side of the bridge, according to witnesses.
Police have confirmed that “a number of people have been stabbed”.
A Met spokesman said: “Police were called at 1.58pm to a stabbing at premises near to London Bridge. Emergency services attended, including officers from the Met and City of London Police.
“A man has been detained by police. We believe a number of people have been injured.”