A man has been arrested by German police after a Manchester City supporter was left fighting for his life following the club's Champions League game against Schalke.
Gelsenkirchen police said a 30-year-old suspect was arrested following "a violent clash" shortly before Wednesday's last-16 first leg at the Veltins Arena.
He has not been named but police said the suspect was a member of the group of Schalke fans known as the "Hugos".
The victim, a 32-year old who has also not been publicly identified, has brain injuries and remains in a critical condition.
A statement from police in Gelsenkirchen said: "The police arranged a homicide division to help investigate the case.
"Their extensive investigations directed to the contemporary identification of a suspect. The 30-year old man from Gelsenkirchen is a member of the so-called 'Hugos', a problematic grouping of fans.
"The public prosecutor of Essen requested a writ of pre-trial custody at the responsible district court. The district court corresponded to that request.
"The 30-year-old was arrested on 25 February 2019 at 10 am at the Vinckestrasse in the district of Buer in the city of Gelsenkirchen. He was then transferred to the correctional facility."
Police have said the City fan suffered a "massive trauma to his skull and brain" after being punched and landing badly on the ground in a skirmish with two Schalke supporters.
It is understood the man had been at the game with his parents and sister, and the family regularly travel to City matches together.
City won the match 3-2 after coming from behind with late goals from Leroy Sane and Raheem Sterling.
The sides are due to meet again at the Etihad Stadium on March 12.