An exclusion zone goes into force in November with one month to go before the Winter Olympics . Rules are imposed on air , sea and road traffic in the Sochi area . Experts say Sochi is well protected but the bombs could hit softer targets . No group has to date claimed responsibility for the attacks , but suspicion has fallen on Chechen separatist groups . One U.S. man says he canceled his Sochi trip after bombings in Volgograd .
An exclusion zone goes into force in November with one month to go before the Winter Olympics . Rules are imposed on air , sea and road traffic in the Sochi area . Experts say Sochi is well protected but the bombs could hit softer targets . One U.S. man says he canceled his Sochi trip after bombings in Volgograd .