Thousands of trade union members and activists around the world marked May Day on Wednesday by marching in major cities, demanding better working conditions and expanding labour rights.

French police clashed with stone-throwing protesters who set fires and smashed vehicles as thousands of people started marching in Paris for rallies under tight security.

Riot police repeatedly used tear gas and sting grenades to try to control the crowd gathering near Montparnasse train station for the main protest. It wasn’t immediately clear how many people were injured. At least two men with head wounds were helped away from the scene by paramedics.

Associated Press reporters observed groups of hooded people in black shouting anti-police slogans, mixing with other protesters wearing yellow vests or waving union flags.

An injured protester in Paris was helped away from the scene by street medics after clashes before the start of the traditional May Day labour union march. (Gonzalo Fuentes/Reuters)

Some threw rocks and other objects at police officers, attacked a parked van in a nearby street, kicking the vehicle and breaking its windows.

Paris police said 55 people were arrested in the Montparnasse area, out of a total of more than 200 arrests on May Day. Officers also carried out more than 12,500 “preventive searches” of bags. More than 7,400 police were deployed in Paris.

Eventually, a vast majority of peaceful protesters started marching through the streets of Paris. They were heading toward Place d’Italie in southern Paris.

Some posters read “long live freedom, long live socialism” and “police, gendarmes, join us.”

Far-left politician Eric Coquerel, member of France Insoumise (Rebel France) said, “Violence is unfortunately often playing against protesters … That’s the number of protesters that will be more efficient.”

French authorities warned “radical activists” may join the Paris demonstration and renew scenes of violence that marked previous yellow vest protests and May Day demonstrations over the past two years.

Yellow vests joined traditional May Day union march to show their common rejection of French President Emmanuel Macron’s economic policies.

Multiple rallies in Russia

Activists said more than 100 people were arrested across Russia — with more than half of the detentions in St. Petersburg for participating in an unsanctioned political protest.

The OVD-Info group said at least 68 people were detained in Russia’s second-largest city in an anti-government contingent that authorities had sanctioned as part of the main May Day demonstration. Two people reported injuries.

Police brutally manhandled people in the opposition contingent, including local lawmaker Maxim Reznik. He was released quickly because of his status as a public official.

Reznik told the Dozhd TV station that officers detained almost everyone in his protest group and would not give the reason for the arrests.

Some of the activists were carrying placards saying, “Putin is not immortal” in reference to President Vladimir Putin who has been at the helm of the country since 2000. Most of the protesters in St. Petersburg are supporters of opposition leader AlexeiNavalny.

In Moscow, authorities said about 100,000 people are taking part in a rally organized by Kremlin-friendly trade unions in Red Square. Over the years, May Day in Russia has transformed from the occasion for rallies for workers’ rights to an official event carefully orchestrated by Kremlin-controlled groups.

Workers attend a May Day rally organized by the Federation of Independent Trade Unions of Russia in Red Square. (Evgenia Novozhenina/Reuters)

Spain’s workers marched to make their voices heard days before acting Prime Minister Pedro Sanchez starts negotiating with other parties to form a new government.

Spain’s leading unions are pressing for Sanchez to roll back business-friendly labour and fiscal reforms that have remained in place since the previous conservative administration.

Sanchez’s Socialist party won Sunday’s election, but will still need other parties to form a government and pass laws. Sanchez will meet with the leaders of the three other top vote-getters next week.

Demonstrations across Asia

A major South Korean umbrella trade union issued a joint statement with a North Korean workers’ organization calling for the Koreas to push ahead with engagement commitments made during a series of inter-Korean summits last year. Many of the plans agreed to between the Koreas, including joint economic projects, have been held back by a lack of progress in nuclear negotiations between Washington and Pyongyang.

Wearing headbands and swinging their fists, the protesters in Seoul rallied in streets near City Hall, marching under banners denouncing deteriorating working conditions and calling for equal treatment and pay for non-regular workers.

In South Korea, protesters called for better rights for workers and a reduction in working hours. (Ahn Young-joon/The Associated Press)

May Day rallies were also being held in other parts of Asia, including the Philippines, Malaysia, Indonesia, Taiwan, Cambodia and Myanmar.

In the Philippines, thousands of workers and labour activists marched near the Malacanang presidential palace in Manila. They demanded that the government of President Rodrigo Duterte address labour issues including a minimum wage increase and the end of contractualization for many workers.

Police said about 5,000 people joined the march, which comes just over a week before senatorial elections are held in the country. One labour group said its members would not vote for any candidate endorsed by Duterte and burned an effigy of Duterte.

A protester carrying a child participates in a May Day rally in Manila. Protesters in the Philippines are calling for several changes, including a boost in the minimum wage. (Eloisa Lopez/Reuters)

In Sri Lanka, major political parties called off traditional May Day rallies due to security concerns following the Easter bombings that killed 253 people and were claimed by militants linked to ISIS.

Several thousand workers were marching through the streets of Taiwan’s capital city Taipei to demand better working conditions. They carried banners and flags and chanted for more days off and higher overtime pay.

Many wore baseball caps and colourful clear plastic ponchos over their clothes, though a light rain ended as the march got underway. Taiwan’s official Central News Agency said 6,000 people joined the march.