Tunisians defied a police lockdown and blocked roads on Saturday to take part in the country’s largest protest in years. Riot police and security forces cordoned off swaths of Tunis city center and tried to prevent both cars and people from entering the streets around Avenue Habib Bourguiba, but thousands of demonstrators made it through. Zarzis is also home to a large number of black Tunisians, who constitute between 10 ...