Russian riot police detains protesters of the group "Russia without Putin" during an unauthorised rally in central Moscow, May 31, 2009. Russian riot police detained up to 30 protesters on Sunday as they attempted to stage a protest calling for Prime Minister Vladimir Putin to resign. As protesters unfurled banners calling for Putin to quit office, Russian riot police moved in and made the arrests. REUTERS/Mikhail Voskresensky (RUSSIA POLITICS CONFLICT)