Protesters threw stones and bottles and attacked police officers with sticks in the German port of Rostock today after a demonstration against next week's Group of Eight (G8) summit.
A group of demonstrators set upon police after a series of marches in the town. Reuters witnesses saw demonstrators throwing bottles and cobblestones at riot police, who fired tear gas in response. Several people were detained.
"There was a massive outbreak against police officers. Stones were thrown and they used sticks too," said a police spokeswoman. She could give no details on injuries or the number of people detained.
Other reports said police baton-charged a crowd of protesters.
It was reported that a small minority of protesters clad in black started the trouble but that it was brought under control.
Masked left-wing demonstrators at the protest. AP Photo/Markus Schreiber
According to police around 20,000 people gathered in the city to protest against the G8 summit in Heiligendamm from June 6th to 8th. Police said around 500 potential troublemakers were among the crowd. The organisers said around 80,000 people attended today's protest.
The thousands of anti-globalisation protesters have converged on the Baltic port to voice their distaste for the policies of the world's leading industrial countries.
Police are expecting up to 100,000 demonstrators to pack the city ahead of the G8 summit next week. About 40 separate gatherings are planned over the weekend.
Gerhard Hahn, anti-globalisation activist
Trains travelling to Rostock yesterday were packed with protesters, some of whom gathered on the harbour front to listen to a rock concert on a warm evening in the city, 200 km (120 miles) north of Berlin on the Baltic coast.
Eager to avert scenes of violence that have accompanied past G8 summits, German leaders including chancellor Angela Merkel have issued pleas for peaceful demonstrations.
However, shopkeepers in the main commercial district of Rostock were prepared for vandalism. Workmen laboured late into Friday night to board up store fronts and protect against damage. Police were visible throughout the town.
Demonstrators have been energised by a series of police raids on leftist activists and police orders for them to stay far away from next week's G8 meeting at nearby Heiligendamm.
Earlier today, a diverse group of protesters marched through Rostock on a cold, overcast day to the harbour where they were gathering for speeches and a music concert later in the day. Their anti-G8 slogans ranged from "Stop Privatisation!", to "World Peace Now!" and "Water Is A Human Right!".
Around 16,000 police officers are on duty in the week leading up to the meeting, amounting to Germany's biggest security operation since after the second World War.
Heiligendamm is about 25 km west of Rostock. A 12-km fence has been erected around the village and protesters will be kept far away, according to the latest court ruling. Protesters are challenging that order at a higher court.
Protesters are expected to block roads leading to Heiligendamm during the summit. They may also disrupt the arrival of some delegates with their plan to blockade the nearby military airport at Rostock-Laage early next week.
German Interior Minister Wolfgang Schaeuble has defended controversial measures such as scent profiling and the option of putting potential troublemakers in protective custody as necessary precautions.
A rally of the extreme right-wing National Democrat Party (NPD) was also to take place today in the town of Schwerin.
A statement issued on behalf of a German anti-fascist alliance said today's march in Schwerin is to counter a neo-Nazi march led against the G8 by the German Nationalist Party Demonstration in Rostock.
It said the neo-fascist group was hoping to "promote its own self interest and anti-Semitic conspiracy theories by manipulating the public fears and growing insecurities created by neoliberal economic policies".
Activist Gerhard Hahn saud: "This development has to be stopped. On June 2nd we will hold a resolute demonstration to prevent nationalists, anti-semitists and Holocaust revisionists from spreading their misplaced anticapitalism to a broad public.
"Our aim is to make visible the anti-fascist character of the alterglobalization movement and our ideas for an emancipatory society."
Ms Merkel will host the US, British, French, Italian, Japanese, Canadian and Russian leaders to discuss hedge fund transparency, African aid and climate change in the summit starting next Thursday.
In 2001, a demonstrator was shot by police in Genoa at a G8 meeting. Since then, G8 summits have been surrounded by heavy security.