Left-wing political groups and trade unions are staging rallies across Europe, the Middle East and Asia on Friday to mark International Workers Day.
Most events are expected to be peaceful protests for workers’ rights and world peace, but May 1 regularly sees clashes between police and militant groups in some cities.
Police and May Day demonstrators clashed in Istanbul as crowds determined to defy a government ban tried to march to the city’s iconic Taksim Square.
Security forces pushed back demonstrators using water cannons and tear gas. Protesters retaliated by throwing stones and hurling firecrackers at police.
Authorities have blocked the square that is symbolic as the center of protests in which 34 people were killed in 1977.
Turkish newswires say that 10,000 police officers were stationed around the square Friday.
The demonstrations are the first large-scale protests since the government passed a security bill this year giving police expanded powers to crack down on protesters.
Thousands of people marched in the capital Seoul on Friday for a third week to protest government labor policies and the handling of a ferry disaster that killed more than 300 people a year ago.
Demonstrators occupied several downtown streets and sporadically clashed with police officers. Protesters tried to move buses used to block their progress. Police responded by spraying tear gas. There were no immediate reports of injuries.
South Korean labor groups have been denouncing a series of government policies they believe will reduce wages, job security and retirement benefits for state employees.
In financially struggling Greece, an estimated 13,000 people took part in three separate May Day marches in Athens, carrying banners and shouting anti-austerity slogans. Minor clashes broke out at the end of the peaceful marches, when a handful of hooded youths threw a petrol bomb at riot police. No injuries or arrests were reported.
Earlier, ministers from the governing radical left Syriza party joined protesters gathering for the marches, including Finance Minister Yanis Varoufakis — who was mobbed by media and admirers — and the ministers of labor and energy.
In the northern city of Thessaloniki, police said another 13,000 people took part in three separate, peaceful marches.
In Moscow, tens of thousands of workers braved chilly rain to march across Red Square. Instead of the red flags with the Communist hammer and sickle used in Soviet times, they waved the blue flags of the dominant Kremlin party and the Russian tricolor.
Despite an economic crisis that is squeezing the working class, there was little if any criticism of President Vladimir Putin or his government.
Participants said the May 1 march was a tradition going back to their childhood. This Soviet nostalgia was imbued with feelings of patriotism in the run-up to the 70th anniversary of victory in World War II on May 9.
The Communist Party later held a separate march under the slogan “against fascism and in support of Donbass,” with participants calling for greater support for the separatists fighting the Ukrainian army in the Donbass region of eastern Ukraine.
Police in Berlin say the traditional `Walpurgis Night’ protest marking the eve of May 1 was calmer than previous years.
Several thousand people took part in anti-capitalist street parties in the north of the city. Fireworks and stones were thrown at police, injuring one officer. Fifteen people were detained. Elsewhere in the German capital revelers partied “extremely peacefully,” police noted on Friday morning.
At noon, Green Party activists unveiled a statue at Alexanderplatz in central Berlin of Edward Snowden, Julian Assange and Chelsea Manning, considered heroes by many on the left for leaking secret U.S. intelligence and military documents. The statue, called “Anything to say,” depicts the three standing on chairs and is scheduled to go on tour around the world.