Tear gas fired in Paris and Istanbul

Violence as people around the world rally for jobs, better working conditions

French and Turkish police fired tear gas at protesters as tensions erupted in both countries during May Day rallies on Sunday, while thousands marched across the globe for the annual celebration of worker's rights.

From Moscow to Madrid, workers chanted demands for higher wages, better conditions and more job security as many countries battle economic uncertainty and high unemployment.

Thick clouds of tear gas hung above the Place de la Nation square in Paris where youths in balaclavas and ski masks lobbed cobblestones and bottles at black-clad riot troops shouting: "Everyone hates the police."

Police estimated some 17,000 protesters marched through the French capital for a rally riding a wave of anger against planned labor reforms set to come before parliament on Tuesday.

The May Day rally was the second protest against the reforms in a week to descend into violence led by troublemakers known as "casseurs" (breakers) who actively seek confrontation with security forces.

"We will respond with the greatest of determination to these troublemakers ... the attacks and violence against security forces are unacceptable," said French Prime Minister Manuel Valls on Sunday.

While the government says it hopes the reforms will reduce chronic unemployment of about 10 percent, critics believe they threaten hard-won workers' rights by making it easier to lay off people in lean times.

Tensions run high

The government has already watered down the bill but this has failed to calm the anger among students and workers.

In Istanbul, police clamped down on unauthorized protests at a time of particular tension after a succession of deadly attacks by suicide bombers this year in Turkey blamed on jihadists and Kurdish militants.

Around 25,000 police were on duty, cordoning off the central Taksim Square and releasing volleys of teargas and water cannon on those trying to make their way to the protest hotspot, an AFP photographer said.

In the flashpoint area of Okmeydani, masked radical leftists threw Molotov cocktails and firecrackers at police and created burning barricades out of junk.

The office of the Istanbul governor said that 207 people were detained around the city for trying to march on Taksim.

Five Seattle police officers were injured and at least nine people arrested on Sunday night, after unruly demonstrators hurled projectiles and broke windows, authorities said.

Mayor Ed Murray blamed the "senseless violence" in Seattle on a "different crowd" from those who had attended an earlier peaceful May Day immigration march.

In posts on social media website Twitter, the Seattle police department said one officer had suffered a cut to the head as protesters hurled Molotov cocktails, another was hit by a rock, and a third officer was bitten, apparently by a protester.

International Workers Day was started in Chicago in 1886 by a union demanding an eight-hour work day and is now celebrated around the world.