BERLIN German police were bracing for more May Day violence on Friday after demonstrators left over 50 riot police injured in Berlin and Hamburg during angry protests over the economic crisis.
In scattered outbursts of violence in Germany's two largest cities in the early morning hours of Friday, 200 demonstrators chanting anti-capitalism slogans threw bottles and stones at riot police while in Hamburg others smashed a bank window.
A total of 57 people were detained in Berlin for rioting or resisting arrest while 48 officers were hurt after five cars were set on fire and four portable toilets torched, police said.
"On the one hand there are people out in the streets protesting peacefully against the economic crisis and there's nothing at all wrong that," said police spokesman Frank Miller.
"But when people burn cars and trash containers and commit other criminal acts -- that has nothing to do with political protests," he told N-TV television at the scene of one especially fiery riot in the eastern district of Friedrichshain.
Germany is facing its worst recession since World War Two with the economy forecast to contract by 6 percent in 2009, while some economists are forecasting unemployment to rise to nearly five million next year.
The trouble in Berlin on Friday began at the end of an otherwise peaceful gathering of about 2,000 people, police said. Demonstrators threw bottles and stones at trams and cars. Glass windows at bus stops were also destroyed by rioters.
Police in Berlin expect further violence when members of far-right parties, labor unions and leftists march.
In Hamburg, authorities said three riot police were injured in clashes with demonstrators.
Rioting on the May 1 Labor Day holiday, which since it started in 1987 has caused extensive damage to parts of the city, had been on the wane in the last three years after police shifted tactics from battling rioters to de-escalation.
May Day is traditionally marked by union rallies in many European countries and the global economic downturn is expected to swell the crowds this year.
"The crisis that is dominating us was caused by unscrupulous speculators," said Michael Sommer, head of the DGB Labor Federation in a May Day speech to a rally in Bremen.
"This crisis is worse than anyone expected. There is no light at the end the tunnel."
The economic crisis has also exacerbated public anger over a growing disparity in wages and the "gentrification" of some low-rent districts.
Frank-Walter Steinmeier, who is leading the Social Democrats into the September election against Chancellor Angela Merkel's Christian Democrats, said he understood workers' rage.
"The crisis is a result of greed and irresponsible actions," he told a rally in Ludwigshafen. "We need a new direction. That's what this May 1 is such a special May Day. It's a day of disappointment and outrage."
(Writing by Erik Kirschbaum; Editing by Richard Hubbard)