Istanbul Basaksehir's players, closely followed by their opponents Paris St Germain, walked off the pitch during a Champions League soccer game on Tuesday after the Turkish club accused a match official of racism.

Basaksehir's Cameroonian assistant coach Pierre Webo was shown a red card for protesting against a refereeing decision and the Turkish side then left the field after about 10 minutes of discussions with Romanian referee Ovidiu Hategan.

PSG then also left the field at the Parc des Princes.

"Our players have taken a decision NOT TO go back on the pitch after our Assistant Coach Pierre Webo has been exposed to racist behaviour by the 4th Official," Istanbul Basaksehir said on Twitter.

The game, which was suspended in the 13th minute, did not resume and European soccer's governing body UEFA said the rest of the match had been rescheduled for Wednesday at 1755GMT.

"Following an alleged incident involving the 4th official, the match was temporarily suspended," UEFA said in a statement.

TV footage showed fourth official Sebastian Coltescu saying in Romanian: 'The black one over there. Go and check who he is. The black one over there, it's not possible to act like that' after Webo vehemently protested against a refereeing decision.

"Why he say negro?", Basaksehir substitute Demba Ba repeatedly asked match referee Hategan as confusion reigned on the touchline in the Group H match.

TV footage also showed PSG's French defender Presnel Kimpembe saying 'Is he serious? We are heading in. We're heading in. That's it, we're heading in."

After confirming that the match would resume on Wednesday, UEFA added that it "will be conducting a thorough investigation.

"Racism, and discrimination in all its forms, has no place within football," the governing body said in a statement.

Turkish president Tayyip Erdogan said on Twitter he believed UEFA would take the necessary steps.

"We are unconditionally against racism and discrimination in sports and in all areas of life," he wrote.

Basaksehir posted UEFA's 'No to Racism' banner on Twitter, a post that was retweeted by PSG on their own official account.

PSG qualified for the last 16 of Europe's leading club competition, despite their match being suspended and then rescheduled, after Manchester United lost 3-2 at Leipzig.

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