Dortmund on final warning for tense Ruhr derby
The German Football Association (DFB) has issued Borussia Dortmund with a final warning to control their fans while local police expect crowd trouble for Tuesday's home derby against Schalke 04.
Tension is high for the derby at Dortmund's Westfalenstadion with third-placed Schalke just a point behind rivals Borussia in the table and violence has marred recent meetings between the teams.
There were around 200 arrests after rival fans clashed when Dortmund last hosted the derby in October 2012 and there was rioting before last October's game in Gelsenkirchen.
Around 3,000 police officers are expected to be on duty on Tuesday in one of the biggest police operations for a German football match.
The kick-off has been brought forward to 2000 local time and police say they expect around 500 violent fans from both teams while 90 individuals have already been banned.
The DFB will be paying close attention having fined Borussia 60,000 euros (US$82,764) and threatened sanctions on Friday after Dortmund fans were involved in incidents at three separate league matches.
Rioting broke out at last October's Ruhr derby in Gelsenkirchen at Schalke's Veltins Arena when a group of Dortmund fans stormed into an area of the ground for home fans.
Flares were thrown into adjacent blocks with three landing on the pitch which delayed the kick off.
Then in last November's 3-0 home defeat against Bayern, Munich goalkeeper Manuel Neuer was pelted by Dortmund fans with "lighters, beer cups and cans" in his own area.
And in February, a fan wearing Dortmund's yellow and black colours shouted the Nazi salute "Sieg Heil!" during a minute's silence at Hamburg in memory of the away club's icon Herrmann Rieger.
In a statement, the DFB's disciplinary committee fined Borussia 30,000 euros for the three incidents and ordered them to invest the same amount in security projects.
In addition, Dortmund will be made to close their famous South Stand for one league match if there is any more trouble "and the enforcement of this measure shall be suspended for seven months on probation".
Dortmund CEO Hans-Joachim Watzke told German broadcaster ZDF he hopes for a peaceful derby, but "those who exercise violence must be outlawed.
"Football is a direct reflection of society and the problem can only be solved if football and the legislators work hand in hand.
"A really peaceful derby would be a great message, especially for the Ruhr."
Dortmund's fans chanted "We want to win the derby!" after Saturday's 3-0 win at Hanover 96 and coach Jurgen Klopp insisted "99.9 percent of our fans are outstanding".
Schalke have worked with Borussia in a bid to help Tuesday's match pass without incident, including separate routes to the ground for both sets of fans.
The clubs and local police have issued a statement urging fans to behave.
"Support your team, and hope for a derby which will be all fired up on the pitch, but please remain peaceful and distance yourself from the hooligans," the statement read.