Police investigating a racist tweet sent to Rio Ferdinand have arrested a 15-year-old boy.
The Manchester United centre-half was targeted on the social networking site during Sunday's derby win at Manchester City.
And Greater Manchester Police confirmed a teenager has now been arrested and bailed on suspicion of a racially aggravated public order offence.
Nine men are already facing prosecution over other incidents at the Etihad Stadium.
Among them is City fan Matthew Stott, 21, who had to be restrained by goalkeeper Joe Hart as he tried to confront Ferdinand on the pitch.
Ferdinand also suffered a cut to his face after he was hit by a coin thrown from the stands.