More than 300 people were arrested and nearly 50 police officers wounded overnight on Wednesday in continued unrest in Tunisia over price hikes and austerity measures, the interior ministry said.
In the town of Thala, located near the border with Algeria, protestors torched the region's national security headquarters, prompting police forces to retreat and authorities to deploy soldiers.
Peaceful demonstrations erupted last week, but turned violent on Monday and Tuesday as they spread to more than 20 towns including in the suburbs of the capital, Tunis. Fresh clashes were reported across several towns for a third night on Wednesday.
Anger has boiled over since the beginning of the year due to a hike in value added tax and social security contributions as part of austerity demanded by international creditors. More than 600 people have been arrested this week for their part in the unrest.
Tunisia has been praised for its democratic transition following the 2011 revolution that ousted authoritarian President Zine El Abidine Ben Ali and sparked the Arab Spring in North Africa and the Middle East.
But the country remains plagued by high unemployment and economic woes that nine governments since the revolution have been unable to address. The 2011 Arab Spring uprising and two Islamist attacks in 2015 have stymied foreign investment and tourism, which accounts for eight percent of Tunisia's economy.
Government vows to restore order
Activists have vowed to continue protests until the austerity measures are reversed, with more major rallies planned for Friday and Sunday, coinciding with the seventh anniversary of Ben Ali's fall.
Read more: Tunisia protests: Is there a trade-off between a strong economy and democracy?
The government has threatened to crack down on violent protests involving looting and burning of buildings and clashes with police. In some towns, protesters burned tires to block roads and threw stones at police.
On Tuesday, suspected Islamists threw petrol bombs at a Jewish school on the tourist island of Djerba.
Read more - Tunisia's Jewish population determined stay despite anti-Semitic violence
One protester was killed on Monday, fueling anger although police said they were not responsible. There is no available figure on the number of injured protesters.
The military has been deployed to protect government buildings, banks and stores, the defense ministry said.
"What happened is violence that we cannot accept. The state will remain steadfast," Prime Minister Youssef Chahed said in a video broadcast by local radio.
Protests are common in Tunisia in January, when the country marks the anniversary of the revolution that ousted Ben Ali. The demonstrations are largely driven by economic grievances.
The Tunisian revolution and Arab Spring started in December 2010 after street vendor Mohamed Bouazizi burned himself to death in the town of Sidi Bouzid in protest over unemployment, poverty, police harassment and graft.
dm, cw/se (AFP, AP, Reuters)