Tunisian authorities said Friday the number of people detained in a wave of violent protests had risen to nearly 800, as fresh unrest over austerity measures hit a provincial town. Activists and opposition politicians appealed for fresh demonstrations in the capital, Tunis, on Friday and on Sunday, the seventh anniversary of the toppling of former President Zine El-Abidine Ben Ali.

An Agence France-Presse (AFP) correspondent in the northern town of Siliana reported that police fired tear gas at dozens of youths who pelted them with stones for some three hours overnight. But the situation appeared calm in other flashpoint towns and neighborhoods across the country that had seen clashes that left dozens of police officers injured.

Protests, some violent, flared across Tunisia on Monday, when one protester was killed, before ebbing on Thursday. Protesters have burned dozens of state buildings, prompting the government to send the army into several cities and towns.

On Thursday, unrest was limited to sporadic clashes in the northern city of Siliana, in Sidi Bouzid in central Tunisia and Douz in the south of the North African country.

"The protests have declined and there was no damage, but last night the police arrested 150 people involved in rioting in the past few days, bringing the total number of detainees to 778," Interior Ministry spokesman Khelifa Chibani said, as reported by Reuters.

Prime Minister Youssef Chahed on Wednesday accused the opposition of fueling dissent by calling for more protests. On Tuesday, petrol bombs were hurled at a Jewish school on the southern tourist island of Djerba, home to an ancient Jewish community.

While Tunisia is widely seen as the only democratic success story among "Arab Spring" nations, it has also had nine governments since the overthrow of Zine El-Abidine Ben Ali, none of which have been able to deal with growing economic problems.

Uprisings in 2011 and two major militant attacks in 2015 damaged foreign investment and tourism, which accounts for 8 percent of Tunisia's economic activity.

Protests are common in the North African state in the month of January, when Tunisians mark the anniversary of the 2011 revolt. The country has been hailed for its relatively smooth democratic transition but seven years after the revolution tensions over economic grievances are high.

Tunisia has seen several days of demonstrations after activists and politicians denounced hikes in value-added tax and social contributions introduced at the start of the year as a tough new budget was implemented.

Tunisia's economy has struggled since the revolution, with growth remaining slow. January 2016 saw the biggest wave of public discontent since the uprising as the death of an unemployed protester in Kasserine sparked days of unrest.

In December, unemployed protesters and activists marched through the streets of Sidi Bouzid, angry over the lack of jobs and opportunities that continue to plague residents. The revolution in Tunisia began in the town in December 2010 after street vendor Mohamed Bouazizi set himself on fire and later died in a protest over unemployment and police harassment that spiraled into Ben Ali's overthrow.