Carlisle manager Keith Curle has condemned an incident of reported racist abuse from the crowd during the 3-0 FA Cup defeat by Everton.
The incident occurred after Everton celebrated Arouna Kone's opening goal, prompting an announcement over the stadium's public address system.
Curle said: "It is not accepted at all. Both clubs don't want anything to do with racism."
The Football Association confirmed it was investigating the incident.
Referee Lee Mason reported a complaint from a player to the managers, who agreed that fans should be told over the PA system that abuse would not be tolerated.
Curle's Everton counterpart Roberto Martinez said players Arouna Kone and Steven Pienaar had been "hurt" by the incident.
"I think they were sensitive and hurt at that moment - probably they were fearful about the game developing into a difficult afternoon," he said.
"There is no room for that sort of behaviour. But it was a very small minority and I want to believe that it was just an emotional reaction to the disappointment of conceding a goal."
The FA said in a statement: "We have received the referee's report regarding the alleged incident during today's game between Carlisle United and Everton.
"We have contacted both clubs this evening and will be conducting an immediate and thorough investigation.
"The FA strongly condemns any discriminatory behaviour and will continue to work with partners across the game to combat it whenever it arises."