Turkish police fired teargas at a wheelchair basketball game after fights broke out between rival fans who also injured several athletes and trashed their wheelchairs.
Supporters of two of Istanbul's top teams, Galatasaray and Besiktas, started brawling at the game.
The violence escalated after small groups chanting offensive slogans carried the row to the sidelines of the basketball court, where they wrecked players' wheelchairs and ripped equipment to pieces.
Police used teargas and the game was cancelled.
It was the first time hooligan violence had wrecked a game for the disabled in Turkey.
The bitter rivalry among Istanbul's main teams, also including Fenerbahce, frequently turns violent in football derbies, where supporters are not allowed to attend away games to avoid clashes.