Shocking footage shows a group of around 20 men and women throwing punches and kicking each other during a fight which broke out in the venue on Sunday night. The violence, which is thought to have been sparked by drinks being thrown, erupted as Olly Murs took the stage to join Robbie Williams (right) for their duet 'Kids'. During the melee, at least one man appears to have his shirt ripped off and another is shown holding another to the ground as he throws repeated blows. A spokesman for Wembley said security personnel intervened and police were called but no further action was taken as no individual wished to press charges.