In debt-crippled Greece, more than 2,000 people marched through central Athens in subdued May Day protests centered on the country's harsh austerity program.
"(We need) new policies that will satisfy the needs of workers and not of bosses and banks," said Ilias Vrettakos of the ADEDY union.
In Moscow, the mood was resolutely pro-government, as 100,000 people — including President Dmitry Medvedev and President-elect Putin — took part in the main May Day march.
The two leaders happily chatted with participants as many banners criticized the Russian opposition movement. One read "Spring has come, the swamp has dried up," referring to Bolotnaya (Swampy) Square, the site of some of the largest opposition demonstrations.
Communists and leftists held a separate May Day rally in Moscow that attracted about 3,000. Communist Party leader Gennady Zyuganov decried international economic troubles, saying that "without socialism, without respect for the working people who create all the main value in this land, it is not possible to get out of this crisis."
Police arrested 22 people at the rally, and violence was largely contained at the protests.
After a workers' day march in Santiago, Chile, some protesters threw objects at closed businesses, breaking the windows of several banks and pulling out furniture to build a bonfire in the street. Police responded with tear gas and water cannons, and arrested an undetermined number of people. In Argentina, small explosion went off outside the EU headquarters in Buenos Aires before dawn, breaking a few windows, but there were no injuries and no one was arrested.
Earlier, thousands of workers protested in the Philippines, Indonesia, Taiwan and other Asian nations, demanding wage hikes. They said their take-home pay could not keep up with rising food, energy and housing prices and school fees.
An unemployed father of six set himself on fire in southern Pakistan in an apparent attempt to kill himself because he was mired in poverty, according to police officer Nek Mohammed. Abdul Razzaq Ansari, 45, suffered burns on 40 percent of his body but survived.
In Manila, capital of the Philippines, more than 8,000 union members clad in red shirts and waving red streamers marched under a brutal sun to a heavily barricaded bridge near the Malacanang presidential palace, which teemed with thousands of riot police.
Another group of left-wing workers later burned a huge effigy of President Benigno Aquino III, depicting him as a lackey of the United States and big business. Aquino has rejected their calls for a $3 daily pay hike, which he warned could worsen inflation and spark layoffs.
In Indonesia, thousands of protesters demanding higher wages paraded through traffic-clogged streets in the capital, Jakarta, where 16,000 police and soldiers were deployed. Protests were also held in Taiwan, Malaysia and Hong Kong.
In Havana, Cubans marked May Day not with protest but with a mass demonstration dedicated to "preserving and perfecting socialism," the slogan on a huge banner carried by medical workers who led the march. Thousands filed through the capital's Plaza of the Revolution in front of President Raul Castro and Cabinet officials, waving red, white and blue Cuban flags.
Thousands in Venezuela held separate May Day marches in Caracas, one praising President Hugo Chavez for signing a law that reduces the workweek to 40 hours and another rally protesting the law's passage without input from businesses and labor unions.
"It's sad that democracy is slipping out of our hands," said Jesus Pinto, a security guard and Chavez opponent.
Contributing to this report were Jim Gomez in Manila, Philippines, Jim Heintz in Moscow, Nicholas Paphitis and Demetris Nellas in Athens, Niniek Karmini in Jakarta, Johanna Decorse in Toulouse, France, Fabiola Sanchez in Caracas, Venezuela, Peter Orsi in Havana, Terry Collins in Oakland, Calif., and Verena Dobnik in New York.