A statement on the club website reads as follows:
West Ham United would like to thank all supporters who have purchased a ticket to support the team in the Barclays Premier League match away at Tottenham Hotspur on Sunday 6 October.
A London derby is always a passionate affair and, as ever, we know the players will be backed by a loud and proud travelling support.
However, the Club seeks to remind all fans attending the match at White Hart Lane that they will be acting as ambassadors for West Ham United and their behaviour should reflect the values and standards of our Club. The corresponding fixture last season was followed by media reports of inappropriate chanting and gesturing by a small minority of individuals in the away end. Any such behaviour is completely unacceptable and will not be tolerated by West Ham United.
The Club, along with the Metropolitan Police, will continue to adopt a zero tolerance policy towards any form of discriminatory behaviour this year and any fan found to be acting inappropriately - including racist, anti-Semitic and homophobic behaviour - will be punished to the full extent of the law and banned from attending matches.
West Ham United is rightly proud of its world-famous support home and away and will not allow the reputation of the tens of thousands of Hammers fans who follow the Club over land and sea to be tarnished by any unacceptable conduct from a small minority.