Twenty-nine Berlin riot police were injured, one seriously, in clashes with rock-throwing demonstrators during the night ahead of planned May Day protests.
A Berlin police spokesman said the violence erupted shortly before midnight in a park in the eastern district of Prenzlauer Berg. He said demonstrators threw rocks, bottles and even shot fireworks at the helmet-clad police. A total of 97 people were arrested.
Elsewhere, hundreds of thousands of workers in Japan turned out for nationwide rallies, urging the government and businesses to protect jobs, as the unemployment rate hovered near a record high.
Police estimated some 223,000 unionists turned out for May Day events held nationwide.
In Turkey, riot police detained 30 left-wing protesters who gathered to mark May Day, the Anatolia news agency reported.
Calling the protest illegal, truncheon-wielding police charged on the demonstrators in centrally located Taksim square on the city's European side after they refused to disperse. Some demonstrators were injured during the scuffles, Anatolia said.
In Indonesia, thousands took to the streets calling for the resignation of President Megawati Sukarnoputri and her manpower minister for alleged indifference to the plight of workers.
In Jakarta about 2,000 workers picketed the presidential palace, calling Megawati and Vice President Hamzah Haz "lackeys of imperialists and anti-workers".
Moscow saw 15,000 Communists waving red flags march through the centre of the city, demanding the resignation of President Vladimir Putin's government.
The march, attended mainly by elderly Communist sympathisers, wound its way down a major city thoroughfare across the river Moskva and past the Kremlin to Lubyanka square, where the former KGB headquarters is located.
Britain is preparing for a series of events in major cities. Campaigners are arriving in central London to take part in the annual May Day protest this afternoon, with police hoping to avoid any violence.
Agencies