A 15-year-old girl has been killed in a stabbing in Croydon, south London.
A number of police vehicles and ambulances can be seen surrounding a red double decker bus in Wellesley Road, near the Whitgift Centre.
A teenage boy was arrested after the girl died at the scene at 09:21 BST, and a murder inquiry has begun. Police believe he may have known the victim.
The Metropolitan Police said it had worked with British Transport Police (BTP) to “track” the teenager.
Ch Supt Andy Brittain, of the Met, said: “Our immediate thoughts are with this young girl’s family who are facing the most tragic of news. Our officers are with the girl’s family to support them.
“I am in contact with the local community, who are clearly as concerned as we are about this tragic incident. I shall continue to update them throughout the day.”
London Ambulance Service says it sent several ambulance crews and London’s Air Ambulance to the stabbing, which happened at about 08.30 BST.
A white forensic tent has been erected within a police cordon outside the Whitgift Centre and a bunch of flowers can be seen placed next to the tent.
The police cordon also surrounds a red double decker number 60 bus, and about a dozen police officers and several emergency vehicles remain in the area.
Mayor of London Sadiq Khan said he was “absolutely heartbroken” by the killing and appealed for witnesses, adding he had been in touch Metropolitan Police Commissioner Sir Mark Rowley.
“I promise to continue working day and night to end the scourge of knife crime in our city,” he told Greatest Hits Radio.
Croydon South MP and Minister for Policing Chris Philp said news of the girl’s death was “devastating”.
“Nothing can be worse for a parent than losing a child,” he said.
“We must redouble our efforts to take all knives off the streets of London, using every means available.”
Steve Reed, MP for Croydon North, called it “another tragic, shocking and avoidable loss of life”.
Mayor of Croydon Jason Perry also said he was “devastated to hear that the teenage girl who was stabbed in the town centre this morning has tragically died”.
“The council are in touch with the police and will fully support their investigations. Our whole community’s thoughts are with the victim’s family and friends.”