The army deployed to the cities of Sousse, Bizert, Kasserine and Seliana only to protect some government buildings, defence ministry official Mohamed Zekri told Reuters.
Tunisian authorities said earlier that they had arrested 240 people, mostly teenagers, after violent clashes with police in several cities overnight and during the day on Sunday.
A decade on from a revolution against poverty, corruption and injustice, Tunisia has progressed towards democracy but its economic problems have worsened, with the country on the verge of bankruptcy and public services in a dire situation.
The protesters made no clear demands in demonstrations – which authorities described as riots – in at least 10 cities around the country.
In the run-down Ettadamen area of the capital, protesters, most of them teenagers, blocked roads and threw stones at police. Police fired water cannons and tear gas to disperse them on Sunday.
Clashes also spread to the Mnihla area of Tunis.
Mhadia, Sousse, Bizert, Kairaouan, Kebeli, Seliana, Nabeul, Manouba Gafsa and Monastir were among the cities that saw violent protests on Sunday.
Witnesses told Reuters that protesters looted shops in several cities.
A video posted online showed young men driving a police car. Reuters could not independently verify the footage.
Internal Security Forces spokesman Walid Hkima said riot police arrested 242 people, mostly teenagers and young people who vandalised property and tried to rob shops and banks.
The protests pose a challenge for the government of Hicham Mechichi, who has reshuffled his cabinet amid an ongoing battle for political influence.
Rural central and southern regions of the country remain flashpoints for rioting.
In Jelma town in the governor of Sidi Bouzid, police dispersed youths who blocked roads and burned tires to protest against their marginalisation and poverty.
Read the original article onAhram Online