Police say a teenager has been arrested for a racist offense at the League Cup semifinal between London rivals Tottenham and Chelsea.

The Metropolitan Police did not specify which team the 17-year-old supports, only saying he was held for a "racially aggravated public order offense."

The force's football unit wrote on Twitter that "the male is currently being dealt with at a North London police station."

Before the game at Wembley Stadium, the Met Police tweeted to say it was working with clubs "to ensure hate crime, including racism and anti-Semitic language, is tackled robustly. Any instances of such behavior will be taken seriously and thoroughly investigated."