Everton have warned fans not to wear club colours if they are travelling to Croatia for Thursday’s Europa League second leg match against Hajduk Split.
Crowd trouble marred the first leg of the play-off at Goodison Park, causing play to be suspended in the 33rd minute, with Uefa opening disciplinary proceedings against both clubs.
Split police says anti-social behaviour will be “dealt with robustly”.
Toffees fans have also been advised not to display flags in any public areas.
Supporters have also been advised to congregate at a specially created fan zone in the city and will be given a police escort to the stadium.
Everton take a 2-0 lead into the match as they aim to reach the Europa League main draw.