At least 200 people were injured when demonstrators demanding jobs clashed with police on Tuesday and Wednesday in Siliana, a city on the edge of the Sahara whose inhabitants have long complained of neglect.
Protesters and a prominent leftist politician called upon Prime Minister Hamadi Jebali to step down after the violence. A leading trade union had called for the protests.
“In democratic systems, we don’t force down governments. I’m not going to resign or dissolve the government. It’s parliament that has authority to do that,” Jebali told a news conference.
“We know who is behind these events – the opposition parties,” he said.
The state news agency said police had used tear gas to try to break up further demonstrations on Thursday.
The protests are the fiercest since hardline Salafi Islamists attacked the U.S. embassy in Tunis in September over an anti-Islam film made in California. That violence left four people dead.
The government led by the Islamist Ennahda party to which Jebali belongs has sought to revive the economy after a fall in trade with the crisis-hit euro zone.
Tension between secularists and Salafis over the direction of the North African state has also hit the economy, which has yet to recover from the instability that followed the toppling of autocratic leader Zine al-Abidine Ben Ali last year.
This week the government secured World Bank and African Development Bank loans of $1 billion to cover its 2013 expenditure, but said it could ask the International Monetary Fund for a $2.5 billion credit line for 2014 and beyond.
Jebali said the latest protests would discourage investors.
“The silence of media and the opposition over the violence against the state threatens our democratic experiment,” he said. “Certain politicians who lost in the elections want violence and disorder.”
Jebali has accused both Salafis and liberal elites of harming Tunisia’s economy and image through their conflict with each other. Ennahda tries to present itself as a middle way between liberals and Salafis.
“We have rejected the violence of people who want to impose their way of life under the pretext of religion, and we refuse the violence of these people too,” he said.