Traditional May Day or International Workers' Day celebrations have taken place in more than 80 countries around the world - and in some cases they have been marked by violent protests.

A general strike has been called in Greece to protest against the tough austerity measures implemented in the debt-ridden country. Hundreds of people rallied in the streets of Athens, demanding an end to spending cuts and tax rises.

Leftist demonstrators clashed with riot police in the Turkish city of Istanbul. Security forces used water cannon and tear gas as May Day marchers tried to reach the city's main square which had been closed due to renovation works, authorities said. At least 123 people were left injured.

In France workers and union members held their traditional parade while supporters of the right-wing National Front party gathered outside the Paris Opera House to listen to party head Marine Le Pen.

Thousands of South Korean workers took to the streets in Seoul to ask for an extensive revision of the labour law, while in the Philippines' capital of Manila, organised labour groups marched to demand a wage increase in place of the package of non-cash benefits announced by President Benigno Aquino.

Demonstrators rallied against a recent pension reform in Taiwan's Taipei, while protesters demonstrated against high living costs and immigration policies in Singapore.

Click through the slideshow to see the most captivating May Day images.

A May Day protestor waves Turkish flags, one bearing a portrait of Mustafa Kemal Ataturk, founder of modern Turkey, as he tries to break through barricades to reach the city's main square in central Istanbul.Reuters
Supporters of the Bulgarian Socialist Party (BSP) march during a rally marking May Day, or Labour Day, in central Sofia.Reuters
A supporter of the Democratic National Alliance opposition party waits in front of the main stage for the start of a May Day rally in Colombo.Reuters
A supporter of the Democratic National Alliance opposition party wears a mask of India's Prime Minister Manmohan Singh as he holds a puppet of Sri Lanka's President Mahinda Rajapaksa at a May Day rally march in Colombo.Reuters
A street performer takes a break as he sits next to a banner during a May Day demonstration on Labour Day in the Andalusian capital of Seville.Reuters
Presidential guards are framed through a burned EU flag in front of the Tomb of the Unknown Soldier by the Greek parliament in Athens' central Syntagma square.Reuters
A policeman aligns his shield on the pavement as officers wait for protesters to march during International Labour Day near the Malacanang Palace in Manila.Reuters
Supporters of France's National Front political party hold flags and banners as they gather outside the Paris Opera House.Reuters
German riot police officers watch the crowd as a protestor gestures during a May Day demonstration in Berlin.Reuters
A supporter of the Bulgarian Socialist Party (BSP) shields herself from the sun with balloons during a rally marking May Day, or Labour Day, in central Sofia.Reuters
An injured journalist is filmed and helped by his colleagues during clashes between riot police and May Day protesters in central Istanbul.Reuters
Turkish riot police clash with May Day protesters in central Istanbul.Reuters
Protesters react during a May Day protest against high living costs and immigration policies at Hong Lim Park in Singapore.Reuters
A South Korean protester raises his fist in front of a barricade of riot police during a May Day rally at Seoul City Hall Plaza in central Seoul.Reuters
Workers and union members hold banners and flags during the traditional May Day march of the French unions in Marseille.Reuters
A man holds Romania's national flag during a Labour Day rally in front of Victoria Palace, Romania's government headquarters, in Bucharest.Reuters
A May Day protestor throws a stone at riot police in Turkey.Reuters
Protesters from labour unions take part in a Labour Day protest in front of the Chiang Kai-shek Memorial Hall in Taipei.Reuters
Protesters from labour unions tie ribbons with protest slogans on barricades while a police officer records a video of them during a Labour Day protest in front of the Executive Yuan building in Taipei.Reuters