Edgbaston officials are investigating allegations of racist behaviour by members of the crowd during the ongoing Test between England and India.
One account on social media said there was racist behaviour towards India fans in the Eric Hollies stand.
Another stated the “disgusting racism” faced was “some of the worst abuse we’ve ever experienced at a match”.
Edgbaston officials apologised and said they would investigate the matter as soon as possible.
They said in a Tweet: “We’re incredible sorry to read this and do not condone this behaviour in anyway.”
An India fan identifying herself as Reena said: “Had an amazing three days watching Test cricket with some brilliant fans from both teams but today ruined the whole experience.
“Waited a long time for this Test match, what a sad ending.”
BBC Sport has contacted the ECB for comment.
England need 119 more runs to beat India on the final day.