 Fenerbahçe SK and Galatasaray SK are the most popular Turkish clubs; both sides have large fanbases that follow them in domestic and international matches.Football hooliganism is a common phenomenon between their fans in recent years, featuring anything from breaking seats, cursing, fighting, fireworks and street rioting.The hatred is so intense that many violent incidents have taken place in several regions of Istanbul as well as in rest of Turkey, especially before or after a derby.