#Reuters |A riot police officer asks an anti-government protester to leave before a demonstration in capital #Manama, #September21, 2012. Hundreds of protesters on Friday tried to march in the main traditional shopping market to demand Bahrain King Hamad bin Isa Al Khalifah to step down. Riot police fired tear gas and sound grenades to disperse the protesters. REUTERS/Hamad I Mohammed (BAHRAIN - Tags: CIVIL UNREST)