In the western city of Kasserine, police fired tear gas at stone-throwing youths in a second night of unrest, an AFP journalist said.
Clashes also broke out in the eastern town of Jbeniana, where a policeman was injured, and in Tebourba in the north where at least five people were arrested, national security spokesman Walid Hkima said.
The unrest follows the death of 32-year-old journalist Abderrazk Zorgui on Monday after setting himself on fire in Kasserine.
The interior ministry said one person had been arrested for alleged involvement in the desperate act of protest, which triggered an outpouring of anger in the city.
"For the sons of Kasserine who have no means of subsistence, today I start a revolution. I am going to set myself on fire," Zorgui said in a video published before his death.
It was the self-immolation of a street vendor in Tunisia in late 2010 in protest at police harassment that sparked Tunisia's revolution and the Arab Spring uprisings across the rest of the region the next year.
Kasserine was one of the first cities to rise up after the vendor's death, in protests that saw police kill demonstrators.
The unrest spread across the country and led to the overthrow of long-time dictator Zine al-Abidine Ben Ali.
Despite the country's democratic transition since then, authorities are still struggling to improve poor living conditions in the face of rampant inflation and persistent unemployment.
Tunisia's national union of journalists called for a general strike on Jan. 14 to mark the eight anniversary of the revolution.