Hull City have announced that arrests were made following discriminatory chanting by supporters during their 4-0 FA Cup fourth round defeat against Chelsea.
After offensive chanting was heard in sections of the home crowd in the first half, a warning was made over the PA system urging supporters to stop and reminding them that CCTV was in operation.
Another announcement followed in the second half which included confirmation that arrests had been made.
The FA will review the referee's match report before deciding whether to take any further action.
"Investigations are ongoing after officers received multiple reports of alleged abusive chanting at the football match between Hull City and Chelsea at the MKM Stadium in Hull on Friday February 13," said Humberside Police in a statement.
"As a result, four men aged 24-, 45- and two aged 21-years-old, were all arrested at the stadium on suspicion of offensive chanting. The 24-year-old man, the 45-year-old man and one of the 21-year-old men are currently under investigation pending further enquiries. The second 21-year-old man has been released without charge."
In his post-match press conference, Hull City head coach Sergej Jakirovic said: "I didn't hear that [the chanting] and this is not the place for this for sure, in the stadium and also in public as well. This is not good, for sure.
"The stadium is not the place for that and this is the reason why they are arrested."
Chelsea head coach Liam Rosenior added: "Without knowing what has happened, and I don't know, any discriminatory language in any form about anything is unacceptable.
"I hope it gets dealt with. The fourth official mentioned something to me but I was so focused on the game. I honestly don't know what's happened there."
