Players from Paris Saint-Germain and Istanbul Basaksehir walked off the pitch during a Champions League match on Tuesday protesting against racism after a game official used offensive language targeting Istanbul’s assistant manager.

The players didn’t return to the field.

GARBER RECOUNTS MLS SUCCESSES, BUT ACKNOWLEDGES LOSSES

Basaksehir assistant coach Pierre Webo, who is from Cameroon, accused the game’s fourth official, Sebastian Coltescu of Romania, for using a racial term to describe him. Basaksehir striker Demba Ba asked the fourth official whether he would have referenced a player's color if he was white -- before the referee pointed for the players to leave for the locker room.

UAE ROYAL BUYS STAKE IN CONTROVERSIAL ISRAELI SOCCER CLUB

When the head referee asked which coach was meant to receive the card, the fourth referee reportedly said “the Black guy,” according to multiple reports. Players and coaches were reportedly heated about the incident before the referee asked the players to leave for the locker room.

UEFA announced that it would “thoroughly investigate” the incident.

CLICK HERE FOR MORE SPORTS COVERAGE ON FOXNEWS.COM

UEFA added that the remainder of the game will be played on Wednesday with a new set of match officials.

“A thorough investigation on the incident that took place will be opened immediately,” UEFA said in a second statement that announced the remainder of the match was being pushed back a day.

A top official at the anti-discrimination network Fare, which helps UEFA investigate cases, said the decision by players to walk off “lays down a marker in Europe.”

“Many players are fed up with half measures to tackle racism,” Piara Powar, Fare's executive director, told The Associated Press.

The Associated Press contributed to this report.