( CNN ) -- The Tunisian government declared a curfew Tuesday in eight governorates , including the capital city of Tunis , in an attempt to quell violence after protests that included radical Islamists . The 9 p.m. to 5 a.m. curfew was announced by the Interior Ministry and the Defense Ministry `` in the wake of violence carried out by criminal groups against establishments of sovereignty and public and private property , '' a prime ministry communique said , according to the official Tunis Afrique Press . The curfew is to be observed in the governorates of Tunis , Ariana , Manouba , Ben Arous , Sousse , Jendouba , Monastir and the Ben Guerdane delegation in the governorate of Medenine , it said . Medical and night-shift workers are exempted . The announcement came hours after the offices and archives of the public prosecutor were set ablaze , Tunis Afrique Press said . The news agency , citing the Interior Ministry , said 97 people had been arrested since Monday night after rioting by `` criminal groups '' in the capital . `` According to a ministry 's press statement , these groups destroyed and set ablaze public properties , attacked police stations and assaulted policemen and citizens , '' it said . `` These groups include Salafis and persons with criminal records . '' Salafis are ultraconservatives . The North African country touched off the Arab Spring by ousting Zine el-Abidine Ben Ali , who was replaced by a moderate Islamist government . Ben Ali has remained in exile in Saudi Arabia since the January 2011 uprising that forced him from office . He is being tried in absentia in the deaths of dozens of anti-government protesters during the revolt . Ben Ali already has been convicted in absentia and sentenced to five years in prison for his role in a 1991 case in which 17 servicemen were accused of plotting a coup against his regime .
Dawn-to-dusk curfew follows unrest , torching of government offices . Government blames `` Salafis and persons with criminal records '' The curfew is imposed in eight governorates , including the capital . Uprising in Tunisia set off 2011 'Arab Spring '