Schalke issued an apology to Borussia Dortmund youngster Youssoufa Moukoko after he received racist abuse during his match-winning performance for the Under-19s on Sunday.
The 15-year-old scored a hat-trick as his side beat their fierce rivals 3-2, but the match was marred by a torrent of abuse from the home supporters.
Schalke condemned the action of the perpetrators in a post on Twitter and promised that the club will investigate the matter.
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"We can only apologise for the behaviour of some of our fans towards Youssoufa #Moukoko at today's U19s match.