A police officer stands guard in front of a protesters' float featuring radioactive wastes during an annual May Day rally and march organized by the Group of the National Confederation of Trade Unions, commonly known in Japanese as Zenroren, in Tokyo May 1, 2015. Thousands of union workers and activists gathered and marched central Tokyo on International Workers' Day, also known as Labour Day or May Day, to demand higher pay and better working conditions, a halt to nuclear power plants, and protested against war and Japan's Prime Minister Shinzo Abe's administration. REUTERS/Issei Kato