Fifty protesters were injured and 138 were arrested in clashes between trade union members celebrating May Day and police. Thousands gathered at remote sites around the city and marched on Taksim Square, where they were met by police.
The Confederation of Progressive Trade Unions said it expected 500,000 people to gather. No estimate of how many attended was offered.
Turkish Prime Minister Recep Tayyip Erdogan said earlier demonstrators should “give up hope” of massing at the city’s large central square on May Day, a traditional day of social protest and worker solidarity. The square was closed to traffic, beginning early in the morning, and Turkish media predicted 40,000 police would be on duty in Istanbul, 19,000 of whom would patrol Taksim Square.
Twitter accounts of the protest said some demonstrators attacked police with fireworks and other incendiary devices, and a police armored vehicle was set afire. By early afternoon, most large groups of campaigners had been dispersed onto side streets, and police disassembled makeshift barricades installed by some protesters.