Moroccan police arrested 18 people, including under-18s, after there were clashes between fans and the police in Juribga while a first division game was going on.
Police sources said on Monday to 'EFE' that during the game that they reported scraps between fans of OC Juribga and FAR Rabat.
These clashes evolved into "stone throwing", the report says, causing 12 Moroccan policeman to be injured.
The statement explained that the Morrocan justice system have opened an investigation for what happened, and that it is to be managed by the corresponding department.
The Botola League's 12th matchday which happened on Saturday ended in a 0-2 defeat for OC Juribga.
Violence is typical between ultra groups in Morocco, especially from those who support the big sides Casablanca, Raja anad Wydad.
Just one week ago, Moroccan police reported arresting 33 fans suspected of being involved in starting violence after a game between Moghreb and Wyad Casablanca on the 8th January in the northern city of Tetuan.