Higher salaries, better working conditions, maternity leave, minimum wage and an end to discrimination against temporary or foreign workers: These were among the concerns as hundreds of thousands of union members and labor activists rallied around the world to mark May Day.
The tradition of May Day marches for workers' rights began in the United States in the 1880s. It quickly spread to other countries at a time when industrialization pitted poorly paid employees who had few protections and little power against increasingly dominant factory employers and landowners.
Over the decades, the May Day protests also have become an opportunity to air general economic grievances or political demands. Here's a look at Wednesday's protests :
Protest over high speed train in Italy
Two protesters and a police officer were injured in the Italian city of Turin when police blocked a demonstration against the construction of a high-speed rail line between France and Italy, according to Italian news agency ANSA.
Among the protesters were members of the 5-Star Movement, a populist party that is in Italy's ruling coalition but is opposed to the tunnel. One member, Torino city councilor Damiano Carretto, said on Facebook he was hit in the head and on the hand by a police truncheon.
The about 36-mile-long Turin-Lyon High-Speed Train tunnel link, known in Italy as TAV, is a key part of an EU project linking southern Spain with Eastern Europe. But the 5-Star Movement has long opposed the project.
Russian workers march at Red Square
Authorities in Russia said about 100,000 people took part in a May Day rally in central Moscow organized by Kremlin-friendly trade unions on Red Square. Opposition activists said more than 100 people were detained in several cities, including for participating in unsanctioned political protests.
In St. Petersburg, police arrested over 60 supporters of opposition leader Alexei Navalny. Some of them carried signs saying "Putin is not immortal," in reference to Russian President Vladimir Putin, who has been at the helm since 2000.
Police manhandled dozens of protesters in Russia's second-largest city, including lawmaker Maxim Reznik, who was later released. Reznik told the Dozhd TV station that police detained almost everyone in his protest group but gave no reason for the arrests.
Violent May Day clashes in Paris
French police clashed with stone-throwing protesters who set fires and smashed up vehicles as thousands of people gathered for May Day rallies under tight security. About 165 arrests were made.
Police repeatedly used tear gas to try to control the crowd gathering near Paris' Montparnasse train station for the main protest. Some protesters were injured. Associated Press reporters saw groups of hooded, black-clad people shouting anti-police slogans, mixing with other protesters wearing yellow vests or waving union flags.
France's interior minister warned earlier that "radical activists" could join the protests in Paris and elsewhere, and deployed 7,400 police to counter them.
Detentions at Turkey’s May Day rallies
Turkish police detained May Day demonstrators trying to march toward Istanbul's main square, which has been declared off-limits by authorities, who cited security concerns. Still, small groups chanting "May Day is Taksim and it cannot be banned," attempted to break the blockade, with dozens reportedly detained. Taksim Square has held symbolic value for Turkey's labor movement since 34 people were killed there during a May Day rally in 1977 when shots were fired into the crowd from a nearby building.
Sri Lanka calls off May Day rallies
In Sri Lanka, major political parties called off the traditional May Day rallies due to security concerns following the Easter bombings, which killed 253 people and were claimed by militants linked to Islamic State.
May Day paralyzes transport in Greece
Union rallies in Greece paralyzed national rail, island ferry and other transportation services. Hundreds of people gathered in central Athens on Wednesday for three separate marches to parliament organized by rival unions and left-wing groups.
Garment workers protest
Hundreds of Bangladeshi garment workers and members of labor organizations rallied in Dhaka, the capital, to demand better working conditions and higher wages. Nazma Akter, president of one of Bangladesh's largest unions, said female garment workers were also demanding six months of maternity leave and protection against sexual abuse and violence in the workplace.
South Africa’s May Day turns political
An opposition party in South Africa used May Day to rally voters a week before the country's national election. Economic Freedom Fighters members, wearing their signature red shirts and berets, gathered at a stadium in Johannesburg to cheer populist stances that have put pressure on the ruling African National Congress to address topics including economic inequality and land reform.
Low-paid workers protest in Jakarta
Thousands of low-paid workers took to the streets in Indonesia in Southeast Asia's largest economy. Laborers in Jakarta, the capital, gathered at national monuments and elsewhere, shouting demands for higher wages, better benefits and improved working conditions.