A man has been stabbed to death at a busy railway station in south London.
Emergency crews were called to East Croydon railway station just after 16:30 GMT to reports of a stabbing.
The air ambulance was called but the man died at the scene.
Det Supt Gareth Williams from British Transport Police, said the attack – which they are treating as murder – was “deeply shocking” outside “a very busy transport hub”.
“Tragically, a young man has lost his life tonight and I know this will be heartbreaking news for his family,” he added.
“We have now launched a murder inquiry and I am urgently appealing for any witnesses to get in touch.”
He said officers believed the attack happened near the back entrance to the station, near Ruskin Square.
“Alongside the Met, throughout the evening, we’ll be increasing our patrols in the East Croydon area and we have authorised additional Section 60 stop and search powers,” he said.
A Section 60 gives police officers the right to search people within a certain area if they think a person may be carrying a weapon or, in this case, a murder weapon.
London Mayor Sadiq Khan tweeted: “Deeply saddened to learn a young man has lost his life. My thoughts are with his loved ones.”
He said he was in touch with the Met Police and urged anyone with information to come forward.
“Violent crime destroys lives and devastates communities,” he added.
Croydon Central MP Sarah Jones said she was “heartbroken”.
“Our first thoughts are with the family and friends who are facing what nobody ever should,” she said.
“I pay tribute to the work of the emergency services and station staff for their efforts.
“This brutal loss of a young life is another reminder that tackling violence must be our highest priority at every level of government and across our communities.
“I will not stop campaigning on this until our children are safe on our streets.”
London Ambulance Service said it sent two ambulances, two paramedics in response cars, an advanced paramedic practitioner and an incident response officer as well as the air ambulance.
Rail services and Tramlink into East Croydon were not disrupted and continue to run as normal.