Supporters of Workers’ Party of Belgium (PTB) hold placards as they attend a rally to mark International Worker’s Day in Brussels, Belgium on May 1, 2015.Supporters of Workers’ Party of Belgium (PTB) hold placards as they attend a rally to mark International Worker’s Day in Brussels, Belgium on May 1, 2015.Supporters of Workers’ Party of Belgium (PTB) hold placards as they attend a rally to mark International Worker’s Day in Brussels, Belgium on May 1, 2015.Supporters of Workers’ Party of Belgium (PTB) hold placards as they attend a rally to mark International Worker’s Day in Brussels, Belgium on May 1, 2015.: Supporters of Workers’ Party of Belgium (PTB) hold a banner as they attend a rally to mark International Worker’s Day in Brussels, Belgium on May 1, 2015.: Supporters of Workers’ Party of Belgium (PTB) hold a banner as they attend a rally to mark International Worker’s Day in Brussels, Belgium on May 1, 2015.: Supporters of Workers’ Party of Belgium (PTB) hold a banner as they attend a rally to mark International Worker’s Day in Brussels, Belgium on May 1, 2015.: French Minister of Justice Christiane Taubira (L) and Belgian Socialist Party (PS) politician Laurette Onkelinx attend a rally to mark International Worker’s Day in Brussels, Belgium on May 1, 2015.French Minister of Justice Christiane Taubira (C) and Belgian Socialist Party (PS) politician Laurette Onkelinx (3rd L) attend a rally to mark International Worker’s Day in Brussels, Belgium on May 1, 2015.People take part in a demonstration at the Place Rouppe-Rouppeplein in Brussels, marking May Day, on May 1, 2015. Tens of thousands of people across the globe were hitting the streets on May 1 for mass rallies marking International Labour Day.People take part in a demonstration at the Place Rouppe-Rouppeplein in Brussels, marking May Day, on May 1, 2015. Tens of thousands of people across the globe were hitting the streets on May 1 for mass rallies marking International Labour Day.