Pictures of several football fans wanted in connection with trouble that flared at last week's Manchester derby have been released by police.Both Manchester United and Manchester City fans are believed to be behind the disorder, before and during the Carling Cup semi-final on 19 January.
Fifteen people were arrested after "sporadic violence" at the ground.
The second-leg of the semi-final takes place at Old Trafford on Wednesday, with United trailing 2-1.
Ahead of the return fixture, Greater Manchester Police have released CCTV images of men they want to trace.
Bottles thrown
Supt Craig Thompson said: "At last week's match there were a small number of so-called football fans who marred an otherwise enjoyable game.
"The people who caused the disorder are a disgrace to the vast majority of peaceful and genuine fans who simply wanted to enjoy the match.
"When we catch these people, and be assured we will, they could become subject to football banning orders, which in simple terms means they will banned from attending football matches.
"If you recognise the people pictured, please get in touch, we need to find those responsible so we can stop them from ruining matches for anyone else."
After last week's fixture police stressed that the majority of fans were well-behaved.
But coins and seats were thrown by some fans during the match, while police were also pelted with bottles.
Source: BBC Sport
Source: BBC Sport