A 65th-minute goal from Kalvin Phillips saw Leeds move up to second place in the Championship after the hosts ended a week of birthday celebrations to mark their centenary on a winning note in a 1-0 triumph.
But the day was marred by crowd trouble following the end of the game involving visiting Birmingham supporters, who clashed with stewards in the away section and there were further incidents of disorder in the coach park outside Elland Road.
A total of 11 arrests were made, police confirmed.
Chief inspector Jon Arrowsuch, match commander at the game, said: “Police resources were deployed outside Elland Road and officers made 11 arrests in total for offences both inside and outside the ground.
“Clearly, these were scenes no-one would wish to see and we will be examining CCTV footage and working with both clubs as we investigate what took place.
“Anyone who has information about public order offences committed is asked to contact Leeds District Police on 101 referencing Police log 531 of October 19.”
Leeds return to action with a trip to sixth-placed Preston tomorrow night.