A man was Tasered after running onto a train with a knife at Queens Road Peckham station.
Police officers were called at 12.20pm to Queens Road in south-east London amid reports a man was armed with a knife and “having a mental health crisis”, according to the Met.
The man had left in a car and police pursued him down the road, where he got out, ran along a railway line to the station and then boarded a train, still armed with a knife.
Police found him on the train and Tasered him. The man, believed to be in his mid-50s, was detained under the Mental Health Act.
Nobody is believed to have been injured in the incident.
Detective Superintendent Nicky Arrowsmith, from the Met’s Central South Command Unit, said: “This incident highlights the challenges that police officers confront on a daily basis.
“I am very proud of the courage and determination of all the officers involved, and pleased that their work helped ensure no member of the public suffered any harm.”