The English Football Association is investigating apparent anti-Semitic chants by West Ham fans during a Premier League match at Tottenham.
At White Hart Lane, West Ham fans were heard hissing to mock the gas chambers used during the Holocaust. Tottenham is known to have a large Jewish fan base.
Four days after a Tottenham fan was stabbed before a game at Lazio, some West Ham supporters were also heard chanting "Can we stab you every week?" and singing "Viva Lazio."
As the FA decides whether to charge West Ham over the conduct of its fans, the governing body says it is gathering information from Tottenham and West Ham and liaising with the police to see if they plan to take any action.
Tottenham beat West Ham 3-1 Sunday.