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.