Workers in countries all over the world joined marches and rallies on Wednesday to mark International Workers' Day, or May Day, with progressive political leaders joining some events and other protests being quashed by law enforcement.

The Industrial Workers of the World (IWW) was among the organizations that promoted the international event on social media, tweeting, "A fighting workers' union is the answer" to workplace injustice.

Demonstrations in Paris on Wednesday were among the rallies that have grown violent through the years.

Police fired tear gas at protesters as the French government warned the demonstration may be overtaken by vandals.

Other rallies across Europe and around the world remained peaceful, with hundreds of thousands of demonstrators calling on governments to push for family leave laws, fair living wages, and an end to workplace discrimination, particularly against immigrants.

London

Madrid

Dhaka, Bangladesh

South Carolina

Orkney, South Africa

In the U.S., a number of other labor organizations tweeted about the day's significance.

Progressive lawmakers from around the world, including Sen. Elizabeth Warren and Rep. Barbara Lee in the U.S. and British Labour Party leader Jeremy Corbyn, tweeted support for workers who were protesting Wednesday.

May Day's roots date back to the late 19th century in the Chicago, where workers went on strike to protest their long, grueling working hours in unsafe factories, construction sites, and other environments. The protests are credited with beginning the labor movement in the United States.

The labor celebration is now an official holiday in 66 countries.