The centre of Munich was turned into a battleground on Monday after fans from Bayern and Paris Saint-Germain clashed.
According to police testimony, more than 60 masked supporters were involved in the fracas, close to Munich's train station.
Fans were later dispersed by officers wielding batons, and in the aftermath more than 30 individuals who had travelled to see PSG were detained.
Those arrested were subjected to criminal record checks by police and later released.
Three Bayern supporters were also detained and held on assault charges, while one man was treated in hospital for a head wound.
Jupp Heynckes' men will need nothing less than victory by a margin of four goals or more to topple PSG and reach the summit by virtue of a better head-to-head record.