Police: Dortmund fans attack children of visiting Leipzig

Berlin - "Extremely violent" Borussia Dortmund fans attacked terrified children and women from visiting RB Leipzig and police made 28 arrests including for possession of explosives, German authorities said.

A crowd of 81,360 saw Dortmund's 1-0 home win over second-placed RB Leipzig on Saturday, but there were ugly scenes outside Borussia's Signal Iduna Park stadium before kick-off when some of the 8,500 visiting fans were attacked.

"In the build-up to the match, in the Strobelallee area (outside the ground), RB Leipzig supporters were bombarded with stones and cans from Borussia Dortmund fans," police said in a statement.

RB Leipzig was unable to tell SID, an AFP subsidiary, how many of its fans were hurt, but eye witnesses say at least 10 paramedics treated visiting supporters.

Police weighed in with pepper spray and batons and made arrests for possession of explosives, assault, grievous bodily harm, breach of the peace, insulting behaviour and resisting arrest.

"All in all, there was extreme aggressiveness and violence from Dortmund supporters, which was directed against any person recognised as a Leipzig fan, regardless of whether they were small children, women or families," said Dortmund police.

"In connection with this, four officers and a police dog were injured."

Borussia Dortmund said it "deeply regretted the riots" and wished the injured Leipzig fans a speedy recovery.

RB Leipzig, who is backed by energy drinks giant Red Bull, is widely unpopular amongst German fans for the commercialism the club is perceived to represent, but Dortmund fans were particularly unwelcoming.

There were several offensive banners in the Dortmund stadium aimed at RB, including "Burnout Ralph, go hang yourself!" after Leipzig's sports director Ralf Rangnick resigned from Schalke in 2011 with burnout.