An investigation is under way after hundreds of fans were involved in a violent pitch invasion which marred the end of a Carling Cup quarter-final clash.
Five people were arrested and 14 needed hospital treatment when trouble flared following Birmingham City's 2-1 home victory over local rivals Aston Villa on Wednesday night.
The violence came just hours before the vote to decide if England will win its bid to host the 2018 World Cup.
Dozens of police and club stewards struggled to contain the rioting, clashing with floods of City fans who stormed the St Andrew's pitch at the final whistle.
A flare was thrown between the two sets of supporters, while seating was ripped from the stands and hurled onto the turf. A public house outside the ground and parked cars were also vandalised as the violence spilled onto the streets.
Birmingham manager Alex McLeish condemned the trouble saying it reminded him of the "Dark Ages", but claimed it would not affect today's World Cup vote. He told Sky Sports 1: "I don't think that will affect the World Cup bid, I'm sure that's already decided, and let's hope England gets it because it deserves it. It doesn't look good though, when you see fans running on the pitch like that and carrying on. It takes us back to the Dark Ages."
A spokesman for West Midlands Police said today: "Five people have been arrested following sporadic outbursts of disorder at the Birmingham derby yesterday. Officers worked with club stewards to quickly clear the stadium after a number of fans gained access to the pitch and threw missiles.
"Fourteen people, including four police officers, received minor injuries which required hospital treatment. Two police dogs were also injured after they were struck by missiles."
A police-led investigation, in conjunction with the Football Association and Birmingham City, has got under way, with officers sifting through CCTV footage to identify the troublemakers.
England will on Thursday learn if it is to host the 2018 World Cup when Fifa's executive committee members cast their votes at a meeting in Switzerland.
