ISTANBUL — Clashes have broken out between police and protestors in Istanbul as trade unions and campaigners defy a ban on holding a May 1 Workers' Day in Taksim Square. Masked demonstrators who used May 1 as an excuse gathered in the allies of Okmeydanı and turned the streets to a battleground. The demonstrators threw stones at the police in Okmeydanı. A police officer was drenched in blood during the events after stones hit him. The injured officer was taken to the hospital.