15-year-old girl was injured in a “malicious attack” when a pint cup filled with coins was thrown during a football match, police have said.
The incident happened at about 8.25pm in the Etihad Stadium at the EFL Cup tie between Manchester City and Liverpool on 22 December.
Manchester Police said the cup was thrown from an upper tier to a lower tier.
The girl is being treated in hospital for a head injury.
Sup Int Gareth Parking said the force would “not tolerate violent or malicious behaviour in any situation, this does not exclude football matches or sports games”.
“We are continuing to investigate this incident and would urge those who attended the game who know who is responsible or could have any information to assist us further, to please come forward,” he said.
Manchester City won the tie 3-2.