Premier League rivals Tottenham and Arsenal have issued a joint statement condemning some chants from supporters during Sunday's north London derby.
The clubs say they will be "working closely with each other to identify the individuals involved."
Referring to the deadly attack on the Togo team in 2010, a section of the visiting Arsenal fans chanted "it should have been you" to former Gunners striker Emmanuel Adebayor.
Some Tottenham fans were also heard to direct chants at Arsenal manager Arsene Wenger branding him a pedophile.
The joint statement says "neither club tolerates foul language, racist chanting, homophobic chanting or any anti-social behavior from its supporters."
Tottenham beat Arsenal 2-1 at White Hart Lane.