The official statement from West Ham reads: "West Ham United would like to make all supporters aware that there will be increased security activity taking place at this Saturday’s match against Tottenham Hotspur, for the safety of all supporters and to prevent any fans of the away club from gaining access to home sections of the stadium.
"Half-and-half scarves or items illustrating the colours/crests of both clubs will not be permitted inside London Stadium on Saturday. Supporters who have purchased half-and-half scarves from unofficial sellers will be required to hand them over to security staff at the security checkpoints and these scarves will not be returned."