Police from Knurow, in southern Poland, arrested nine people on Tuesday after riots broke out on Monday night following the death of a football fan, allegedly killed by a rubber bullet fired by security forces.
Groups of fans attacked the police with Molotov cocktails, rocks and metal objects, Efe news agency cited police spokesman Andrzej Gaska as saying on Tuesday.
Unrest continued for the third consecutive day between rioters and police forces, while 30 people were arrested on Monday.
The 27-year-old Knurow fan is thought to have died when police attempted to control fans rushing the Concordia Knurow field during a Polish league match against Ruch Radzionkow on Saturday; the local team won 4-1.
Police have opened an investigation to determine the cause of the fan's death.