Left-wing protesters set fire to barricades in clashes with police
Thousands of left-wing demonstrators gathered to protest against an extreme right-wing rally have clashed with police in the German city of Cologne.
Police said about 3,000 protesters threw stones at officers, while some tried to steal their weapons.
Violence erupted after the protesters tried to halt an "anti-Islamification" rally, which police eventually banned.
The extreme-right Pro-Koeln group had sought to protest against plans to build one of Europe's biggest mosques.
The police said the decision to ban the rally was a matter of public safety.
Some 3,000 police had been drafted in and part of the old city was sealed off as authorities appealed for peaceful protests against a two-day congress called by the Pro-Koeln (Pro-Cologne) group.
The mosque is not due to be completed until 2009
Pro-Koeln had hoped 1,500 people would attend the rally in the city centre to oppose the mosque and what they say is an "immigrant invasion" of Europe.
The municipal council has approved the building of the domed mosque, which will have two 55m (177ft) minarets, in the city's heavily immigrant Ehrenfeld district.
Far-right leaders from Belgium, Austria and Italy had come to the city for the congress.
It was due to culminate in a rally against "Islamification" and in support of Europe's "shared, 1,000-year history" and "Western values and Christian traditions".
Earlier, the leftist demonstrators blocked two Pro-Koeln leaders from entering the conference venue, pursuing them as they sought refuge on a boat.
Police say they responded with batons after left-wing protesters set fire to barricades.
In a speech earlier on Saturday, Cologne Mayor Fritz Schramma labelled Pro-Koeln "arsonists and racists" hiding under the cloak of a "citizens' movement".
Germany is home to three million Muslims, who make up 4% of the population.