Riot police officers wearing gas masks wait in front of a monument of Ataturk, founder of modern Turkey, to stop May Day protesters from forcing their way into Taksim Square in Istanbul May 1, 2007. Turkish police detained 580 people in Istanbul on Tuesday in street battles with leftist demonstrators protesting on the May Day anniversary of a mass shooting 30 years ago. Police charged at hundreds of protesters, many from leftist organisations, kicking and clubbing them in the city's main Taksim Square and neighbouring streets. REUTERS/Fatih Saribas (TURKEY)