Rioters burn a policeman’s hat during clashes with the police in downtown of the capital Tunis January 14, 2011. Tunisian President Zine al-Abedine Ben Ali declared a state of emergency on Friday and warned that protesters would be shot in an increasingly frantic effort to quell the worst unrest in his two decades in power. REUTERS/Zohra Bensemra (TUNISIA – Tags: POLITICS CIVIL UNREST MILITARY)