Trade union members march in May Day celebrations in downtown Kiev on Saturday. About 4,000 people rallied in Ukraine's capital. (Sergei Chuzavkov/Associated Press)

Millions of people marched in cities around the world Saturday to mark May Day, or International Workers' Day, as they rallied for better work conditions, higher wages and laws that are more just.

Demonstrators poured into the streets from Hong Kong to Moscow to Santiago, Chile, waving flags, beating drums and dancing to music.

About 140,000 jubilant workers gathered in Istanbul's Taksim Square in the first celebrations at the site since dozens of people died there in a May 1 gathering more than three decades ago.

The Istanbul demonstrations marked a special victory for Turkish unions, which had been denied access to Taksim Square since 1977, when 34 people died after a shooting triggered a stampede. The culprits were never found and workers on Saturday demanded an inquiry into the demonstrators' deaths.

'I reject the five per cent increase,' says a La Paz demonstrator's sign denouncing the size of Bolivia's proposed minimum-wage increase. (Juan Karita/Associated Press)

Thousands joined peaceful May Day marches in Stockholm, where opposition leader Mona Sahlin blamed the centre-right government for failing to stem rising unemployment and eroding the nation's cherished welfare system. Sahlin is hoping to become Sweden's first female prime minister after national elections in September.

In Manila, Philippine President Gloria Macapagal Arroyo announced she had ordered the labour secretary to speed up negotiations between unions and employers on a $1.70 increase in the daily minimum wage.

In Toronto, a few thousand demonstrators pressed for reforms to make it easier for refugees to seek haven in Canada and for immigrants to come to the country.

In Indonesia's capital, Jakarta, thousands of workers marched on the presidential palace, shouting: "Workers unite! No more layoffs!" Rally organizer Bayu Ajie said a free-trade agreement with China had cost jobs, decreased wages and encouraged corruption. President Susilo Bambang Yudhoyono promised to create safer working conditions and improve job prospects if the workers maintained political and economic stability.

Kasparov leads rally

France saw rallies that drew hundreds of thousands of people to the streets of Paris, Marseille, Lille and other cities, but the turnout nevertheless disappointed labour unions that had been hoping for crowds in the millions to provide a show of force against a planned pension overhaul.

A rare opposition march took place in Moscow, where former world chess champion Garry Kasparov, now an opposition politician, led activists calling for the ouster of Russian Prime Minister Vladimir Putin, whom they accuse of stifling democracy.

In La Paz, the Bolivian capital, marchers carried signs denouncing the government's proposed five per cent hike in the minimum wage as too paltry.

About 1,000 protesters — among them bus drivers and janitors — took to the streets in Hong Kong to demand that the government enact a minimum wage of the equivalent of $4.35 an hour. Though the Chinese territory has some of the richest residents in the world, its wealth is too unevenly distributed, advocates say.

People participate in a May Day protest in San Salvador, El Salvador. (Edgar Romero/Associated Press)

Most of the annual May Day marches were peaceful, but in Santiago, clashes broke out with police, who launched tear gas and deployed a water cannon against demonstrators.

Athens also witnessed riots, with police using tear gas to disperse demonstrators who threw firebombs and stones in a large rally against austerity measures imposed to secure loans for near-bankrupt Greece.

In Switzerland, Zurich police used water cannons in an attempt to disperse dozens of stone-throwing protesters as unions and politicians protested against "excessive" Swiss banking bonuses.

German police detained 250 neo-Nazis who attempted to attack them in downtown Berlin.

The turnout in Cuba was massive, as expected, and authorities asserted the march by hundreds of thousands of Cubans amounted to approval of the island's Communist system amid mounting international criticism over human rights. A smiling President Raul Castro watched the rally go past from a high podium.

With files from The Associated Press