Swiss club FC Zurich have condemned fans who threw a banana at rival player Aldo Kalulu when he went to take a corner during their league match at FC Basel on Sunday.
Zurich admitted the banana came from the part of the St Jakob Park stadium occupied by their supporters.
"In the early stages of [the match] against Basel, a banana was thrown out of FCZ's fan zone towards FCB player Aldo Kalulu when he went to take a corner," the club said in a statement.
"The club strongly condemns this racist behaviour and does not tolerate it in any way. There is no room for xenophobia and discrimination in football.
"FCZ has always been committed to diversity and welcomes all people, regardless of their background or religion."
Kalulu, a Frenchman of Rwandan descent, was also pelted with cigarette lighters when he went to take the corner in the ninth minute of Basel's 2-0 win, media reports said. The 22-year-old joined Basel in June from Olympique Lyonnais.
The Swiss Football League has yet to comment on the incident.