The fresh protests draw on anger over price and tax increases included in this year's budget that took effect on January 1.
Activists and the opposition have called for fresh protests on Sunday, the seventh anniversary of the toppling of autocrat Zine El-Abidine Ben Ali, the first leader to fall in the 2011 "Arab Spring" protests that swept the region.
A man in his 40s died in unrest on Monday night in the northern town of Tebourba though police have insisted they did not kill him.
The government of Tunisia has made a decision to use units of the army due to mass protests in the country caused by high prices and taxes.
Interior ministry spokesman Khalifa Chibani said 151 people were arrested Thursday, taking the number detained for alleged involvement in the violence to 778 after several nights of unrest. "The state will remain steadfast", Prime Minister Youssef Chahed said in a video broadcast by local radio after he visited towns hit by clashes. The economy worsened since a vital tourism sector was almost wiped out by a wave of deadly militant attacks in 2015, and has yet to recover despite improved security.
The previous day, petrol bombs were hurled at a Jewish school on the southern tourist island of Djerba, home to an ancient Jewish community.
Tunisian protesters confront security forces blocking access to the governorate's offices in Tunis during a demonstration over price hikes and austerity measures on January 12, 2018.
The main labour union and Islamists, who co-rule with secular forces, had demanded an increase in aid for poor families after the protests began.
In a written statement, Rupert Colville, spokesperson for the Office of the UN High Commissioner for Human Rights, said authorities must ensure that people are not arrested in an arbitrary manner and that their rights are respected.
The protests have drawn in hundreds in each town where they have taken place, though they have been smaller than previous waves of demonstrations since 2011.
Protests were held over rising prices of fuels, mobile phone fees, cosmetics and internet tariffs, and the new finance law which increases certain taxes.
There was no immediate response from the government.