May Day protesters from the far right, far left and all shades in between took to streets around the world yesterday, some brimming with nationalist fervor, others calling for peace, jobs and a better environment.
Anarchists, Trotskyists, trade unionists, anti-globalization activists, even sex workers, were out in force, but so were the army and police.
An opposition leader in Singapore was among dozens of individuals arrested in connection with protests across Asia.
Chee Soon Juan, the leader of the Singapore Democratic Party, was arrested after he tried to stage an illegal rally outside the presidential complex to mark Labor Day, police and witnesses said.
Chee was warned by police that he could not proceed with the rally without a permit and was shoved into a van amid protests from a crowd of about 15 when he went ahead.
In Germany, one woman was fighting for her life after violence marking May Day erupted in two leftist districts of Berlin. It began when a group of around 500 anarchists lit a large fire on a main street and then pelted the fire brigade with bottles and stones.
Police used water cannon against the demonstrators and hundreds of riot police moved in. Dozens of people suffered facial cuts from hurled bottles after what was planned as a peaceful anti-Nazi demonstration.
Scores of cyclists converged on the US embassy in London, blocking traffic at the start of anti-pollution and anti-capitalism protests which drew thousands of demonstrators to the British capital.
Amid fears a hard core of activists were bent on violence, up to 6,000 police flooded the city and businesses boarded up their windows.
Almost every country in the world marks May day in one way or another, and the date is officially recognized by the UN as International Labor Day.
In other world capitals, trade unionists marched in more traditional May Day parades, calling for better workers' rights and an end to violence in the Middle East.
"Long live international solidarity to Palestine," read a red banner in Syndagma Square in central Athens, where thousands of demonstrators had gathered.
In Australia, where trade unions still have much influence on government, police arrested dozens of people after scuffles broke out at a picket to protest against the country's immigration policies.
Although thousands of people also staged peaceful labour demonstrations, union officials expressed concern their cause was being hijacked by fringe groups.
"It's the traditional day of international solidarity for working people. The methods used to promote these other causes are a concern for us ... detract from May Day," said John Robertson, secretary of the New South Wales Labor Council.
In Moscow, pro-Kremlin parties and trade unions stole the show from the communists by staging an estimated 140,000-strong rally on the Red Square -- something the country has not seen since the Soviet days.
President Vladimir Putin welcomed the demonstrators. In a message that was read out to the well-organized flower-waving crowd, he hailed the action by the unions and the Kremlin's key ally United Russia bloc as helping build a better future.
The communists held a rally nearby to demand an immediate government resignation.
Authorities in China, which once derided private enterprise as evil capitalism, showed just how much things had changed by canonizing entrepreneurs as "model workers," awarding special medals to successful businessmen.