Thirteen football fans have been arrested after violent clashes erupted between rival supporters watching a derby match.
West Midlands Police criticised the behaviour of a "small number" of spectators who "behaved dreadfully" during and after the Championship game between Wolverhampton Wanderers and Birmingham City at Molineux Stadium on Friday.
The force said eight of the arrested men are believed to be Blues fans and five are thought to be Wolves supporters.
Police said the trouble began after Birmingham scored a second goal and Wolves fans are believed to have thrown bottles, seats and coins from the Steve Bull and South Bank stands.
Match commander Chief Inspector Nick Rowe, from West Midlands Police, said the vast majority of supporters "behaved impeccably".
"However, a small number of people behaved dreadfully, spoiling the enjoyment for others. A group of people yet to be identified threw missiles inside the stadium," he said.
"After the final whistle, opposing fans clashed near to the train station, police officers issued several warnings but to no avail and were forced to quell the disorder and used appropriate and proportionate force.
"We will look to identify those responsible for throwing missiles inside the stadium and those involved in trouble near to the station, and if necessary they will be prosecuted."
Officers have launched an investigation into the two incidents and are urging anyone who witnessed the disorder or who can identify those involved to get in touch.
Mr Rowe said officers were "faced with a very challenging, yet isolated incident" and had to take further action to "prevent further clashes and other fans getting hurt".
He added: "If we receive any complaints then this will be reviewed by the West Midlands Police professional standards department in consultation with the IPCC (Independent Police Complaints Commission)."
Mr Rowe also revealed that as fans "violently clashed", two officers were saving the life of an elderly Wolves supporter who had "collapsed on a bus with a suspected heart attack".
Anyone with information should call West Midlands Police on 101. Alternatively, information can be left anonymously by calling Crimestoppers on 0800 555 111.