Turkish riot police fired tear gas in the centre of Ankara on Monday night to disperse hundreds of protesters on the 11th day of mass demonstrations against Prime Minister Recep Tayyip Erdogan\'s Islamic-rooted government. Riot police surrounded the affluent Tunali Hilmi street which until now has largely been spared from the riots which have rocked the capital nightly since May 30, forcing restaurant owners to shut themselves in with their clients to escape the gas.