The 21-year-old said on Twitter that he had reported the incident and revealed that he also received abusive responses to his allegations on the micro-blogging website.
England Under-21 international Sordell was an unused substitute, while Lee, Pratley and Afobe all came off the bench in the second half.
"Putting the match aside, its 2012 in england and people are still shouting racial abuse at a football game!? Shocking," Sordell wrote on Twitter.
"Chungy, Pratts, Benik and i had all sorts of things said to us. The police were standing yards away and did nothing.
"Funniest thing is if had come on and scored and gave them some back, i would be the one who got fined."