The clip shows the angry schoolgirl square up to the woman and scream “who’re you talking to?” before smacking her across the face and walking off.

The stunned victim is visibly shaken and begins to cry before a member of the public comes forward to try to comfort her.

Audible gasps are heard from the crowd as others in Hounslow High Street in West London witnessed the horrific assault.

Onlookers can be heard saying “what’re you doing man?” and “oh my God!”