Hibernian vowed to take action after a fan was caught on camera apparently aiming racist abuse at Hearts defender Clevid Dikamona.
Hibs branded the behaviour "unacceptable" after the fan was seen on live television shouting abuse as the French-born Congo international was being told to leave the pitch by the referee following treatment for an injury during Hearts' 1-0 win at Easter Road.
A Hibernian spokesman said: "The club will do everything we can to identify the individual concerned and we will take the appropriate action. It's unacceptable."
The previous Edinburgh derby at Tynecastle saw Hibs head coach Neil Lennon struck by a coin and other missiles thrown at Hibs players and match officials, while a man was later charged in connection with an alleged assault on Hearts goalkeeper Zdenek Zlamal.
