Bulgarians are celebrating Sunday May 1, the international Labor Day marking the struggle for dignified work and the feeling of solidarity amongst laborers.

The history of the commemoration goes back to the 1886 Haymarket incident in Chicago, when a number of protesters - trade unionists and common workers of varying political beliefs - were massacred by police, or hanged after show trials.

Later, in 1890-1 the Socialist International recognized May 1 as an international day to celebrate the struggle for workers' rights.

Massively celebrated in the former Eastern Block, May 1 is also immensely popular with people across Western Europe, with workers traditionally gathering in large rallies on that day.

As such, May 1 is an official holiday in many European countries. Even the Roman Catholic Church has dedicated the day to St. Joseph the Worker.