A 15-year-old girl was left with a one inch cut to her head after she was hit with a cup filled with coins during Manchester City's Carabao Cup clash with Liverpool.
It is believed the cup was thrown inside the Etihad Stadium at around 8:25pm from the upper tier down to the lower tier in the stadium during the EFL tie on 22 December.
The girl was taken to hospital where she received medical attention.
It is understood the cup was thrown from the visiting section into the home end.
Greater Manchester Police (GMP) is now appealing to the public to help locate whoever was responsible for the "malicious attack".
Superintendent Gareth Parkin said: “GMP will not tolerate violent or malicious behaviour in any situation, this does NOT exclude football matches or sports games.
“Clearly throwing objects in a confined area can be dangerous and have serious and sometimes devastating consequences.
“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."
GMP say a "number of objects, including coins and a smoke bomb" were thrown during the match.
Both clubs have pledged to look into the various disturbances while Greater Manchester Police has launched its own investigation following the incidents.
Liverpool disabled supporters also suffered alleged racial abuse, with a City supporter thrown out of the stadium and arrested for a racially aggravated public order offence.
A 53-year-old man was also assaulted after the game at the junction of Ashton New Road and Alan Turing Way. He was treated at the scene and required hospital treatment.
Both clubs had written to fans before the game calling for calm and respectful behaviour.
Two men were arrested on suspicion of trying to take a pyrotechnic into the ground, while another man has been arrested for a racially aggravated public order offence.
All three will be interviewed at a later date.
Anyone with information can call 101 or report information online via GMP's reporting tool quoting log 1880 of 22/12/2022.
In a joint statement the clubs say they will investigate.
The statement said: “Manchester City FC, Liverpool FC and the chairs from our supporter groups have worked together in recent weeks to remind fans of our expectations and both clubs would like to thank the vast majority of fans for their behaviour at last night’s Carabao Cup match at the Etihad Stadium.
“It is however hugely disappointing that there were a number of incidents during last night’s match that are wholly unacceptable.
“These incidents will be fully investigated, reported to the police and the individuals who are found to be responsible will be subject to the sanction process of their respective club.
“Manchester City FC and Liverpool FC are fully committed to working together to eradicate these issues from our fixtures. They have no place in football.”
The past few years have seen a number of unsavoury incidents occur between supporters, with the latest meeting at Anfield in October marred by offensive graffiti about Hillsborough being written in the away section and allegations of chanting about the 1989 disaster, in which 97 fans died.
City’s also claimed coins had been thrown at their coaching staff, although a Liverpool investigation failed to find any evidence, and one of their buses was damaged on leaving Anfield.
Manager Jurgen Klopp was also sent off in that game for hurling abuse at an assistant referee, who did not flag for a foul by Bernardo Silva on Mohamed Salah.
Manchester City edged out rivals Liverpool 3-2 in the five-goal thriller to claim a place in the Carabao Cup quarter-finals.
Liverpool had cancelled out City goals from Erling Haaland and Riyad Mahrez through Fabio Carvalho and Mohamed Salah respectively.
But Nathan Ake headed the winner as the Dutchman turned in a superb Kevin De Bruyne cross.
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