In televised scenes reminiscent of the dark days of English soccer hooliganism, hundreds of City fans invaded the pitch to taunt their local rivals after Birmingham's 2-1 quarter-final win at St Andrew's.
Villa supporters reacted by hurling pieces of broken plastic seating and other missiles while both sets of fans threw flares.
West Midlands police issued a statement on Thursday saying five people had been arrested following "sporadic outbreaks of disorder.
"In addition to the damage caused inside the stadium, a pub near to St Andrew's was also damaged as were several parked cars," the statement read.
"Fourteen people, including four police officers, received minor injuries which required hospital treatment. Two police dogs were also hurt after they were struck by missiles."
Superintendent Steve Graham, responsible for policing the game, said: "This incident must have been very frightening for the vast majority of spectators who enjoyed the match and did not cause any problems.
"I'm sure football fans everywhere will join with me in condemning the illegal actions of those who have brought shame on themselves, their clubs and our city.
"An investigation into the disorder has now begun and we will be using CCTV footage to identify those who were responsible."
DAWN RAIDS
Earlier this week West Midlands police arrested seven men in a series of co-ordinated dawn raids on the homes of those suspected of violence at the Villa v Birmingham Premier League derby on October 31. That game ended in a 0-0 draw.
The English FA condemned the violence which could not have come at a worse time for the country's World Cup bid.
With the decision on the 2018 hosts coming later on Thursday, nobody from the bid party was available for comment.
Birmingham issued a statement, saying: "The club does not tolerate the breaking of any stadium rules and will conduct a full investigation in conjunction with the FA and police and take appropriate action.
"A meeting will be held at St Andrew's on Thursday to investigate the matter further."
Acting chairman Peter Pannu said: "While we are very happy with the victory we are extremely disappointed with the events that took place after the game.
"I promise there will be an impartial investigation by the club as we do not condone the embarrassing actions of certain individuals."
