Published on Wednesday, 19 December 2012 14:05 Written by BBC
Landscrona, the Russian champions' largest fans' group, said black players are "forced down Zenit's throat".
"I'm not surprised. Everybody knows Zenit supporters are no good and racist," Samba told BBC Radio 5 live.
"They are living in another century. It's a sad day for Russian football."
He added: "In this time we have different communities and countries that constitute teams. If they can't accept that then they are never going to progress."
Zenit were the only top-flight Russian team without a black player until the summer signings of Brazil striker Hulk and Belgian midfielder Axel Witsel.
The club was fined by the Russian Football Union after one of their fans offered a banana to Anzhi Makhachkala left-back Roberto Carlos before a match between the two sides in March 2011.
Black players in the Russian league have been the target of monkey chants and Samba also had a banana thrown at him by a Lokomotiv Moscow fan shortly after his move from Blackburn Rovers.
However, the Congo-Brazzaville international insists there is no prospect of black players staging a protest by boycotting matches following Landscrona's open letter.
"Boycotting, why? Because fans make statement they don't want black players. No. Black players should fight for the good ones - not the idiots," he said.
"It's really sad. It's slowing down the process of Russian football being a better league. I hope the Russian federation do the necessary to sanction it."
Russia is preparing to host the 2018 World Cup after being picked by governing body Fifa to stage the tournament for the first time.
Samba, 28, believes Russia's continuing problems surrounding racism are "not helping" the country's preparations.
He added: "The fact that a lot of players are going to Russia should be promoted. But if we're not welcome then it would be very difficult to change the mentality ahead of the World Cup."