Liverpool manager Jurgen Klopp faces an anxious wait over the fitness of key midfielder Fabinho over the next 48 hours.
The influential Brazil international has become a major component in the team's rise to the top of the Premier League, but he was forced off with an ankle injury in the 1-1 Champions League draw with Napoli.
He left Anfield with his left foot in a protective boot and Klopp will hope he is not ruled out for any length of time with a packed December fixture schedule coming up.
Three men were detained for violent disorder, one for affray and another for breach of the peace.
"Officers policing the LFC v Napoli CL game have arrested five Napoli fans," said a statement from Merseyside Police.
"Three men were arrested for violent disorder and another was for affray following disorder on Walton Breck Rd before the game.
"A fifth man was arrested for breach of the peace at the turnstiles on Anfield Road."
