Thousands of unions, workers and activists worldwide on Wednesday are marking the International Workers' Day, also known as May Day. May Day first emerged as an event commemorating the labor of workers worldwide on May 1, 1886, when a group of workers in the U.S. held a massive strike for an eight-hour workday. In 1889, the International Workers Conference of Paris declared May 1 an international holiday for workers, in memory of those who partook in that strike. The day soon came to be recognized worldwide as International Workers' Day. First Workers' Day celebrations were held in 1911 in Thessaloniki in Ottoman Empire by tobacco and cotton workers, while first celebration in Istanbul was in 1912. Turkey's first official May Day celebrations were held in 1923. In 1977, Labor Day demonstrations in Istanbul's Taksim Square led to the deaths of 34 and injury of 136 in what became known as Bloody May 1. After the military coup on September 12, 1980, the holiday was suspended and celebrations banned across Turkey.