The arrangement of the Taksim square in central Istanbul for this year's labor day was designed the same way as the 1977 celebrations, with a stage set up on the south side of the square, where union leaders took to the stage and delivered speeches for workers' rights as hundreds of thousands of people assembled at the square, chanting slogans and holding up signs, which read "May 1 for labor, peace, freedom and democracy" and "Happy May 1st."
"The working class is the one that will change the world, its tool is Marxism," read a giant banner propped on the west side of the square.
At the intervals of the speeches, bands gave free performances on the stage for the assembled crowds.
Organizations and political parties such as the Revolutionary Worker's Unions Confederation (DISK), the Republican People's Party (CHP), the Democratic Left Party (DSP) and the Turkish Worker's Unions Confederation held marches Sunday morning from across the city towards the Taksim square.
About 38,000 police force were deployed in the main streets of Istanbul leading to the Taksim square to maintain the security.
Traffic to the square has been blocked since 7 a.m. as police barricaded the perimeter.
Celebrating worker's day in the Taksim square has become a matter of pride for Turkish unions, while the violence during the 1977 celebrations prompted the government to ban celebrations there until 2010.
Half a million of people gathered in the square in 1977 when unidentified assailants fired on the crowds, causing chaos that resulted in 34 deaths and 136 injuries.
Violence often broke out between workers trying to celebrate in the square and police trying to keep them out until 2010, when celebrations were allowed again.
Turkey has a total population of 74 million. The unemployment rate in the country was 11.9 percent in 2010.
