The FA have started an investigation into the scenes that marred the Second City derby at St Andrew’s on Sunday.
Birmingham have been asked by the governing body to provide observations after a number of Aston Villa players were targeted by missiles.
Dozens of clappers placed on seats before the game were thrown onto the pitch, while Ahmed Elmohamady was hit by a coin that he handed to a steward.
The FA are waiting for referee Andy Madley’s match report before taking further action, with a linesman also understood to have been struck by something launched from the stands.