Borussia Dortmund and Copenhagen fans were seen throwing flares at each other before the start of their Champions League match at the Westfalen Stadium on Tuesday.
About an hour before kick-off, balaclava-clad Dortmund fans and their Brondby friends made their way to the Copenhagen sector and began throwing flares at the opposing fans, who responded in the same way.
A number of Copenhagen lads also got out of the away end in an attempt to get at their rivals but were beaten back by cops.
