A 15-year-old has been arrested by police investigating a racist tweet sent during Manchester football derby on Monday.
The teenager was held for a night on suspicion of a racially aggravated public order offence.
Police say an investigation was launched after a message was directed at a Manchester United player.
The boy has been bailed pending further inquiries.
United defender Rio Ferdinand was injured during the match.
He was left with a cut to his left eyebrow after being hit by a coin while celebrating his team's winning goal at the Etihad Stadium.
Nine people were charged after the match between Manchester City and Manchester United on Sunday.
Police have appealed for anyone with information about people throwing coins to contact them.