Russian Premier League club Anzhi Makhachkala has called for an end to "bigotry" in domestic football after its fans were abused by CSKA Moscow supporters.
Throughout CSKA's 1-0 home win over Anzhi on Saturday, CSKA fans shouted derogatory slogans about the Caucasus region. They also displayed a banner bearing the words "animal planet" with a modified Anzhi crest featuring an apparent anti-gay slur.
Anzhi fans typically hail from ethnic minority groups in the Caucasus.
In a statement issued on Sunday, which was headed "we demand football is protected from bigotry," Anzhi's general director Sergei Korablev asked law enforcement and football authorities to investigate the incidents.
"The CSKA fans' chants included insults directed at our club and fans, expressions which provoke hostility on the basis of ethnicity," he said. "Unpunished aggression from fans will inevitably lead to a rise in the number of such incidents."
Some CSKA fans said they were also abused by Anzhi supporters, with sexist chants directed at ethnic Russian women.
The Russian Football Union's disciplinary committee is due to meet Wednesday. Its head, Artur Grigoryants, told Russian media on Monday that the committee had received a report about the chants and would investigate.
Previously, incidents of fan racism in Russian domestic football have been punished with partial or full stadium closures for the team concerned.
Last season, CSKA played all three of their Champions League group stage games behind closed doors as a UEFA punishment for a string of racist and violent incidents involving the club's fans.
Tensions in Russian society often run high between ethnic Russians and ethnic minority groups, including both foreign migrant workers and Russian citizens from the Caucasus region.
Ahead of Russia hosting the 2018 World Cup, anti-discrimination group FARE produced a report in February listing over 200 cases of racist or discriminatory behaviour in Russian football over the previous two seasons.
Of those, the report described 22 cases of "anti-Caucasus displays" and 15 attacks on people from ethnic groups hailing from the region.
Black players have also faced abuse, with Zenit St. Petersburg striker Hulk saying last month that racism was present at "almost every game" in Russia.