The high risk Euro 2024 match between England and Serbia on Sunday will be safeguarded by a bigger police force than used for matches between local club Schalke and arch rivals Borussia Dortmund.
Police director Peter Both said on Friday he wouldn't give a precise figure "for tactical reasons" but said he has never had as many officers in place at Schalke v Dortmund matches.
Both said he expects some 20,000 English fans and 10,000 from Serbia in the stadium, plus around 15,000 further England fans without tickets set to be in the city's public viewing area. He could not say how many additional Serbia fans would be present.
The match has been declared high risk since the group draw in December due to potential fan violence. In the stadium, beer with less alcohol than usual is served, and cups can not be taken into the stands.
Both said "we have no concrete information on the arrival of groups from England and Serbia who are ready for violence" but they want to be prepared, especially give the number of expected fans without match tickets.
"The fan scene has developed since the last Euros in one country [France] in 2016. It is difficult for us to predict it. That's why we prefer to install a few more safety precautions," he said.
A big security operation is in place for the month-long Euros in 10 German cities which kick off later on Friday. Interior Minister Nancy Faeser has said that some 22,000 police officers will be in place every day to safeguard the event.
