Video has emerged of Boxing Day shoppers fleeing after reports of a man seen holding a machete.
Armed police have reportedly been called to attend the scene at Intu shopping centre in Bromley.
It is understood a woman received knife wounds, and was treated at the scene.
Witness Ceri Harlin, 18, told the Evening Standard: "A police van pulled up and officers went running inside.
"Security and three or four police officers have handcuffed a man and the police officer is carrying the huge knife.
"No-one got injured as far as I know."
Sky News reported that one officer appeared to be holding a confiscated 2ft-long machete.
Whilst one Twitter user uploaded a video appearing to show Police handling the said weapon:
A spokeswoman for the Metropolitan Police said: "We were called at 3.45pm to reports of an injured man at the shopping centre.
"Officers attended the scene and found a man believed to be in his 20s with a minor head injury.
"We believe he sustained it as a result of an altercation.
"The injured man has been arrested for affray and possession of an offensive weapon.
"Officers have recovered two knives and are seeking to trace a man of which we have no further details, who ran off the scene possibly discarding a weapon."
More to follow...