A teenager was held at Taser-point near to Hampstead Heath after reports a rail worker was threatened with a knife.
Images seen by the Ham&High show an officer pointing the taser at a young male near the M&S Foodhall in Pond Street on Sunday (April 2).
Police were called at around 4.45pm to reports of staff at Gospel Oak Station being threatened.
Metropolitan Police says that officers arrested a boy on suspicion of possessing an offensive weapon.
The case was then passed on to British Transport Police.
A spokesperson for the force said two boys, 15 and 16, were arrested on suspicion of possessing an offensive weapon.
They have been released on bail, pending further enquiries.
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